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Best Choice EMSea 
EMSea 2pcs 8mm to 6mm Barb Reducer Tube Mender Splicer Joiner Union Brass Fitting Made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability.EMSea 
EMSea 2pcs 10mm to 8mm Barb Reducer Tube Mender Splicer Joiner Union Brass Fitting Made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability.Nikovoke 
2 Pcs Push Fit Pneumatic Reducer Fittings, Straight Union Quick Connect Tube Connectors for Compressor, Vacuum Systems, 【One push and it connects automatically】No tools required to complete the connection and reconfiguration of industrial pBest Value EMSea 
EMSea 2pcs 12mm to 10mm Barb Reducer Tube Mender Splicer Joiner Union Brass Fitting Made of brass for corrosion resistance, ductility at high temperatures, and low magnetic permeability.eMagTech 
eMagTech 4Pcs 3/8 Male to 1/4 Female Connector Water Pipe Reducer Fittings Thread Reducer Accessories for Pipes Radiator Practical Reducer Adapter: BSP Thread reducer comes in 2 sizes, so you can easily convert the 3/8 inch water pipe into 1Nikovoke 2 Pcs Push Fit Pneumatic Reducer Fittings, Straight Union Quick Connect Tube Connectors for Compressor, Vacuum Systems, 【One push and it connects automatically】No tools required to complete the connection and reconfiguration of industrial pAS Axis Spindleon 
AS Axis Spindleon 2Pcs 3/8" BSPT Male to 1/4" NPT Female Brass Pipe Fitting Reducer Adapter for Pipes Tubes Precise Adapter: Converts 3/8" BSPT male thread to 1/4" NPT female thread easily.Nikovoke 2 Pcs Push Fit Pneumatic Reducer Fittings, Straight Union Quick Connect Tube Connectors for Compressor, Vacuum Systems, 【One push and it connects automatically】No tools required to complete the connection and reconfiguration of industrial pEMSea EMSea 24Pcs Pneumatic Push to Connect Fittings Pipe Joint Kit Reducer Adapter Applications: Used for air compression systems, vacuum systems, pneumatic systems.Push to connect fittings designed forGeneric Generic 10Pcs Hose Fitting PE Tube Connector Barb Reducer Set Kit for Aquarium Fish Tank (6-10mm Conversion Head) [Large Quantity] Includes 10pcs barb tube connectors in the set, fulfilling your working requirements.uxcell uxcell Concentric Reducer Steel Butt Weld 304 Stainless Tube Concentric Reducer and Increaser Pipe Fittings for Food Bev Color: Silver Tone; Material: 304 Stainless Steel; Length: 42 mm / 1.65 Inch; Interface outer diameter 1: 38mm/1.5inch;Malida Malida 1/2" Thread Male to 1/4" Push Fit Tube Quick Connect for Water Purifiers Reverse Osmosis (5pack) 1/2"Thread male x 1/4" tube Quick Connect.Tomvorks 10Pcs PE Tube Connector Barb Reducer Joint Set Kit, Hose Connector, with Different Diameters at Two Ends, Including 10 B [Versatile Application] Suitable for aquariums, fish tanks, and more.X AUTOHAUX X AUTOHAUX Car Engine Hose Fitting Connect Reducer, 12mm-6mm Straight Shape Hose Fitting Splicer Universal for Fuel Air UNIVERSAL FIT - Engine Hose Fitting Adapter universal for most car engine air water gas oil hose connect, durable engineEMSea EMSea 4X Brass 1/2 Inch Female Pipe x 1/4 Inch Male Pipe Reducing Conversion Adapters [Type]:1/2 Inch female pipe to 1/4 Inch male BSP pipe fitting, for most pipes, hoses and taps.Augiimor Augiimor 2Pcs Brass Flare Tube Fitting 5/8 Inch NPT Male x 1/2 Inch Female NPT Pipe Reducer Adapter Brass Reducing Pipe Package Includes: 2Pcs 5/8" Male to 1/2" Female Brass Pipe Fittings, durability and reliable for various hot and cold waRobcseber Brass Hose Barb Fitting, Reducer Tube Splicer Joiner Hose Fitting 19 to 25mm Quick Connector Adapter for Air Fuel Water Quick Barb Joint Connection: Featuring special barb joints for fast and secure attachment to pipes, enabling easy instaluxcell uxcell Straight Push to Connector Reducer Fitting 6mm to 4mm Quick Release Pneumatic Connector Plastic Union Pipe Tube F 5 Pcs for 6mm to 4mm OD plastic straight tube fitting.ULDIGI ULDIGI 10pcs Air Line Push-to-Connect Tube Reducer Fittings 12mm to 16mm Quick Connect Air Hose Connectors for Pneumatic Air brake quick connect fittings--no additional sealing is required, just a simple push provides a secure connection,pneBonsicoky Bonsicoky 304 Stainless Steel Hex Bushing Reducer, 1/2" Male NPT to 1/4" Female NPT, Pipe Hose Tube Adapter Convert for ❤What You Get: 2 x Hex Bushing Reducer, sufficient for your daily use. Size: As shown in the detailed diagram. Please paBonsicoky Bonsicoky 304 Stainless Steel Hex Bushing Reducer, 1/2" Male NPT to 1/4" Female NPT, Pipe Hose Tube Adapter Convert for ❤What You Get: 2 x Hex Bushing Reducer, sufficient for your daily use. Size: As shown in the detailed diagram. Please pa13% Off Generic Plastic Push to Connect Straight Union Pipe Tube Reducer Fitting, 6mm OD x 8mm OD, Reducing Coupler Straight Pneumatic C Reducing coupler for connecting two pipes with different diametersuxcell uxcell 6 Pcs Straight Union Push to Connect Fitting, 1/4" x 3/8" OD Tube Reducer Connector Quick Push Lock Adapter Air H Specification: Color: Black; Material: Plastic, Stainless Steel Circlip; Applicable Range: Fit for 1/4" x 3/8" Pipe Outeuxcell uxcell Straight Push to Connector Reducer Fitting 12mm to 8mm Quick Release Pneumatic Connector Plastic Union Pipe Tube 2 Pcs for 12mm to 8mm OD plastic straight tube fitting.SEIWEI SEIWEI 8Pcs Plastic Hose Fittings Barb Reducer Pipe Connector Two Way Straight Tube Adapter for Garden, Aquarium, Home(2 Durable Material Composition: Crafted from polypropylene (PP), these hose fittings offer excellent resistance to corrosiuxcell uxcell Straight Push to Connector Reducer Fitting 10mm to 6mm Quick Release Pneumatic Connector Plastic Union Pipe Tube 2 Pcs for 10mm to 6mm OD plastic straight tube fitting.Generic Generic 6pcs Push to Connect Air Fittings Tube Reducer Fitting 3/4 Inch to 12mm Pu Nylon Brass High Durability No Additi Push to connect air fittings--0-1 mpa pressure resistance, high pressure resistance, not easy to trip,push to connect tuECSiNG ECSiNG 2pcs 12mm to 10mm Stem Adaptor ATBC1210M for 12mm Push-Fit Connection to 3/8" ID Flexible Hose Hose Adapter: Connects 12mm push-fit fittings to 3/8" (10mm) ID flexible hose, ideal for plumbing, aquariums, and fluidOTOTEC OTOTEC 10PCS 8mm OD Push to Connect Fitting Pneumatic Cap Tubing Quick Cap Plug Fitting Air Tool Accessories for Pipe Tu The 8mm connect pneumatic caps are stuitable for connect polyethylene, nylon and PU tubes, air pipes and pneumatic tools16% Off YINETTECH YINETTECH 5PCS 4mm to 8mm Hose Fitting Hose Connector Plastic Adapter 54mm Length Compatible with Cold Water Nozzle Tube Suitable for bridging cold water hose nozzles of different sizes, used to link 4mm and 8mm cold water hoses, ensuring auxcell uxcell 1/2" to 1/4" ID Copper Reducer, 10pcs 99.9% Pure Copper Reducing Coupling Pressure Fitting Pipe Tube Connector Ad Color: Copper Tone; Material: Copper; Type: Copper Reducer; Bigger End Inner Dia.:12.7mm / 1/2 inch; Smaller End Inner Duxcell uxcell 3/8" to 5/16" ID Copper Reducer, 8pcs 99.9% Pure Copper Reducing Coupling Pressure Fitting Pipe Tube Connector Ad Type: Copper Reducer; Bigger End Inner Dia.:10mm / 3/8 inch; Smaller End Inner Dia.:8mm / 5/16 inch; Thickness.: 1mm / 016% Off YINETTECH YINETTECH 5PCS 4mm to 8mm Hose Fitting Hose Connector Plastic Adapter 54mm Length Compatible with Cold Water Nozzle Tube Suitable for bridging cold water hose nozzles of different sizes, used to link 4mm and 8mm cold water hoses, ensuring aERGAOBOY ERGAOBOY 10 Pcs 12MM Tube OD x 10MM Tube OD Straight Reducing Push to Connect Fittings, Black Pneumatic Tube Reducer Pus Size: 12MM Tube OD x 10MM Tube OD Black Straight Reducing Tube Fittings Push Lock.DERNORD DERNORD Sanitary Fitting Reducer Fitting SUS304 Tri Clamp Ferrule Style 2" Tube OD to 1" Tube OD Concentric reducer fitting to connect two pipes of different diameters that are along the same pipe axisuxcell uxcell Straight Push to Connector Reducer Fitting 12mm to 8mm Quick Release Pneumatic Connector Plastic Union Pipe Tube 5 Pcs for 12mm to 8mm OD plastic straight tube fitting.SEIWEI Pack of 8 Plastic Hose Fittings Barb Reducing Tube Connector Two-Way Straight Pipe Adapter for Garden, Aquarium, Home (6 DURABLE MATERIAL COMPOSITION: Made of polypropylene (PP), these hose connections provide excellent resistance to corrosiSTARTIST STARTIST Square Tube Pipe Bushing 60mm to 50mm Reducer Sleeve for Fitness Equipment, 100mm 【Product Dimensions】: The reducer sleeve has dimensions of 60mm to 50mm, making it suitable for specific pipe fitting neuxcell uxcell Straight Push to Connector Reducer Fitting 12mm to 10mm Quick Release Pneumatic Connector Plastic Union Pipe Tube 2 Pcs for 12mm to 10mm OD plastic straight tube fitting.Liimevvon 20 pcs 3/8" to 1/4" OD Straight Union Reducer, Quick Connect, Push Fit Water Tube Fitting for RO Reverse Osmosis, Water Package Quantity: 20 packap automotive 22mm > 16mm (7/8" > 5/8") Pipe Corrugated Reducing Joiner PVC Barbed Straight Tube Adapter Hose Reducer Fitting Coupling 22mm > 16mm Plastic Inline Hose Reduction Fittinguxcell uxcell 5/8" to 1/2" ID Copper Reducer, 6pcs 99.9% Pure Copper Reducing Coupling Pressure Fitting Pipe Tube Connector Ada Color: Copper Tone; Material: Copper; Type: Copper Reducer; Bigger End Inner Dia.:16mm / 5/8 inch; Smaller End Inner DiaFTVOGUE FTVOGUE Barb Hose Reducer, Premium Brass Pipe Connector, 2pcs for 4-8mm Tubes, Ideal for Plumbing and Maintenance Work [Durable Brass Material]Constructed from premium brass offering excellent durability and reliability for long-lasting usuxcell uxcell Brass Pipe Fitting Reducer Adapter 3/8" BSPT Male x 1/4" NPT Female for Water Oil Air Pressure Gauge Temp Sensor [High-temperature Resistance] - From -65 to 250 Fahrenheit Degreeuxcell uxcell 1 5/8" to 5/8" ID Copper Reducer, 99.9% Pure Copper Reducing Coupling Pressure Fitting Pipe Tube Connector Adapte Color: Copper Tone; Material: Copper; Type: Copper Reducer; Bigger End Inner Dia.:42mm / 1 5/8 inch; Smaller End Inner DOpusBags 10 Pcs M12 to M10 Thread Reducer Nuts Conversion Sleeve - High Strength Steel Threaded Inserts for Pipe Fittings, Z Axis 【Full Threaded Nut】The product features a full thread structure with precise thread processing, enabling tight connectioHALLMERS HALLMERS M8 x 1.0mm Male to M10 x 1.0mm Female Brass Pipe Reducer Fitting Connector Thread Plumbing Hose, Hex Head Threa 1pc Threaded Pipe AdapterMtsooning Mtsooning Brass Tube Adapter, 3/8inch Male Flare×1/2inch Female NPT Pipe Coupling Fittings 【100% SOLID BRASS】: Brass adapter with flared tube connection is made of high-quality solid brass, resistant to high andAcbbMNS AcbbMNS 20Pcs 6mm (1/4 inch) Straight Push to Connect Fittings, Quick Release Pneumatic Connector Air Line Fitting Plast 【Package Included】You will get 20pcs 6mm(1/4") Straight Union Connectors, fit for OD 1/4" tube. Suitable for PU / PA / PSTEBER 6AN Female to 4AN Male Flare Reducer Fuel Line Hose Fitting Adapters Aluminum Reducing Pipe Anodized Black Female AN6 (9/16-18, JIC 6 ) to Male AN4 (7/16-20, JIC 4 ) Threaded tube connectorUenede Uenede 8PCS LF Brass 3/4 to 1/2 to 3/4 Inch PEX Tee Reducer 3 Way Coupling Barb Crimp Pipe Tube Fitting 【Package Include】8PCS 3/4"x1/2"x3/4" Reducer Tee 3 Way PEX Pipe Fitting.Uenede Uenede 8PCS LF Brass 3/4 to 1/2 to 3/4 Inch PEX Tee Reducer 3 Way Coupling Barb Crimp Pipe Tube Fitting 【Package Include】8PCS 3/4"x1/2"x3/4" Reducer Tee 3 Way PEX Pipe Fitting.Generic 10Pcs PP Hose Barb Reducer Fitting Pump Adapter for Silicone Tube Connection Versatile irrigation hose joint, widely suitable for pump pipes and silicone tubesOneyijun Oneyijun 140-180mm ABS Ducting Reducer Round Pipe Multi Reducer Extractor Fan Ventilation Systems Hose Connector Adapter ★ Package included: Duct Pipe Reducer , 2 Meters Thick Aluminum Foil Tape , 100-200mm Adjustable Stainless Steel Pipe Cluxcell uxcell Concentric Reducer Concentric Reducer Steel Butt Weld 304 Stainless Tube Concentric Reducer and Increaser Pipe Fi Color: Silver Tone; Material: 304 Stainless Steel; Length: 60mm ;Interface outer diameter 1: 25 mm / 1 inch;Interface ouTL TOOLEGIN Brass Inverted Flare Fitting, Brake Line Adapter, Male Connector, 3/16" Tube OD x 1/8" NPT Male, 5pcs Adapts NPT male end to flared tubing female end.Generic Generic Ducting Airflow Tube Increaser Adapter 100-75mm Accessory Pipe Fitting for Hotel 【Easy to Install】just connect the two ends of the connector with pipes of appropriate sizeTopHomer 1Pcs 6mm-8mm Two Way Reducing Connector Brass Barb Hose Connector Fitting Tube Reducers Hose Fitting Adapter Connect Wat - Durable and strong.KOOTANS KOOTANS 4pcs Heavy Duty 1/4" NPT Male Thread to 1/8" NPT Female Thread Brass Reducer Hex Bushing Brass Fitting Pipe Hose SIZE: 1/4 NPT male thread to 1/8 NPT female thread hex bushing. PLEASE NOTE, NPT Thread Size is a nominal pipe size andNUSITOU NUSITOU 6pcs 3/8inch Pneumatic Air Line Fittings Quick Release Straight Push Connectors Tube Reducer Fitting Kit for Air Tube fittings:quick and easy installation, just plug into the plastic tube,straight quick connect fittingsHooshing Hooshing 6PCS Brass Reducer Hex Bushing 1/4" NPT Male x 1/8" NPT Female Thread Brass Fitting Pipe Tube Convert Adapter Hex bushing for connecting female and male pipes with different diameters.Megairon Megairon 32MM to 25MM 1.25" to 1" Tube OD Sanitary Concentric Reducer Coupling,Stainless Steel 316 Pipe Fitting 100% Brand new,Wall Thickness:1.5-3MM (increasing with OD)LEONTOOL LEONTOOL 2 Pack Hose Barb Fittings Reducer, 1/4" to 3/8" Brass Hose Barb Reducer with 4 Hose Clamps, Reducing Barb Brabe Package Include: 2 pcs 1/4" to 3/8"(6 to 10mm) 2-Way Reducer Hose Barb Fittings, 4 pcs 304 stainless steel clamps(AdjustCreate idea Create idea 2pcs 1/4 NPT Female Pipe Fitting Adapter 304 Stainless Steel for Pipe Tubes Compatibility: Designed with 1/4" NPT female threads for universal pipe and sensor connections.Jualyue 10Pcs Push to Connect Fittings 10mm Tube ODx6mm Tube OD Reducer Quick Connect Hose Fittings Air Quick Ideal for Home the Reliable Construction: Made from PVC materials, these air quick connect fittings are designed for reliable performance aMAGICLULU MAGICLULU 10pcs Quick Connect Air Hose Fittings Tube Reducer Push-to-Connect Pneumatic Connectors 12mm to 16mm for Air C Ease of use: simple push-in design, attaches to the tube, providing a secure connection without additional sealing,quickNikovoke 10Pcs Pneumatic Push-to-Connect Fittings, Straight Air Hose Connector for Tube OD 6mm 8mm with BSP Thread - 6mmx1/8 6mmx 【Plug-and-Play】 No tools required for quick connection of the hose and threaded interface, providing a modular piping soSpacnana Spacnana Brass Reducer Connectors Tube Reducers Pipe Fitting Adapter (19-25mm) Compact size with good sealing, safe and reliable to use.HALLMERS HALLMERS 3/4" BSP Male to 1" BSP Female Brass Pipe Fitting Reducer Connector Thread Plumbing Hose, Hex Bushing Threaded This is a handy brass barbed fitting commonly used to connect lines for air, water, fuel, oil, and inert gases.ZYWUOY ZYWUOY 1 x 2 Pipe OD to 1.5" Pipe OD Concentric Reducer Plumbing Fitting Reducer SS304 Tri Clamp Fits 2" Tri Clamp / 1.5 ------Made of high quality materials for durability. Widely used in food, pharmaceutical, beer and other industrial fielOdorkle Odorkle Hose Fitting Tube Connector Hose Fitting, Tube Connector Barb Reducer Joint Set Kit for Stable Flows, Suitable f [ABUNDANT QUANTITY] - Set includes 10pcs barb tube connectors to satisfy your working needs.AcbbMNS AcbbMNS 5Pcs Brass Hose Barb Reducer Fittings, 6mm to 4mm Barb Hose Fitting Adapter Straight Union Connector for Air Wat 【Package Included】5-Pack 6mm barb OD to 4mm barb OD Brass Hose Barb Reducer Fittings.uxcell uxcell Concentric Reducer Concentric Reducer Steel Butt Weld 304 Stainless Tube Concentric Reducer and Increaser Pipe Fi Color: Silver Tone; Material: 304 Stainless Steel; Length: 44 mm / 1.73Inch;Interface outer diameter 1: 38mm/1.5inch;Intuxcell uxcell 6 Pcs Y Shape Union Push to Connect Fitting, 3/16" OD Tube Reducer Connector Quick Push Lock Adapter Air Hose Fit Specification: Color: Black; Material: Plastic, Stainless Steel Circlip; Applicable Range: Fit for 3/16" Pipe Outer DiamTopHomer 1/4" 3 Way Tee Three Way Quick Connector, Air Fittings Push to Connect Tube Fitting, Quick Pneumatic Connector Push Conn Premium Material: The pneumatic tube connect fittings are made of high-quality 304 stainless steel, which has good corroHooshing Hooshing 2PCS Brass Pipe Fitting 1/4" NPT Male to 1/2" NPT Female Reducer Hose Tube Adapter PREMIUM MATERIAL - Quality solid brass for corrosion resistance, more durable than iron and iron galvanized pipe fittingSopepoyie 2Pcs Brass Flare Tube Fitting3/8 NPT Male x5/8" Female NPT Pipe Reducer Adapter Brass Reducing Pipe Connector，Pipe Fitti 【Product Type】：3/8" Male to 5/8" Female Brass Pipe Fittings。HALLMERS HALLMERS M12 x 1.5mm Male to 1/4" BSP Female Brass Pipe Reducer Fitting Connector Thread Plumbing Hose, Hex Head Threade 1pc Threaded Pipe AdapterDANAIXZ DANAIXZ 10PCS Hose Barb Reducer Fitting PP Air Pump Adapter for Aquarium Silicone Tube Connection Irrigation Pipe Joint [PREMIUM PP MATERIAL] Made from high-grade polypropylene, these hose barb reducer fittings are completely non-, and rustHALLMERS HALLMERS Brass Straight 25mm Barb Hose to 1/2" BSP Male Threaded Barbed Pipe Fitting Connector, Adapter Coupler Reducer This is a handy brass barbed fitting commonly used to connect lines for air, water, fuel, oil, and inert gases.QANYEGN 2pcs Hex Reducer Bushing, Brass Pipe Hose Tube Fitting, Female Reducer Hose Tube Adapter for Car Accessories BRASS CONSTRUCTION FOR DURABILITY AND RELIABILITY: The Hex Reducer Bushing is made from premium brass, offering strengthTopHomer Straight Pneumatic Fittings, 5PCS 1/4Inch Push to Quick Connect Fittings, Straight Push Fit Connectors Quick Push in Str Premium Material: Pneumatic tube connectors are made of high-quality copper metal with a nickel-plated surface, which pruxcell uxcell Concentric Reducer Concentric Reducer Steel Butt Weld 304 Stainless Tube Concentric Reducer and Increaser Pipe Fi Color: Silver;Material: 304 Stainless Steel;Length: 98 mm;Interface outer diameter 1: 102mm/4inch;Interface outer diametAOPANDA AOPANDA Brass Pipe Fitting 3/8 Male Pipe x 3/8 Female Pipe tube adapter connector thread Brass Hexagonal Pipe Fittings A 【Package include】Brass 3/8NPT Male x 3/8 NPT Female Reducing Hex Nipples，4PCSULTECHNOVO ULTECHNOVO 2pcs 42mm to 75mm Plastic Pipe Reducer Fittings Air Outlet Connector for Diesel Parking Heater Ducting Hose T Improved system protection: the ventilation pipe reducer adapter provides smooth airflow, protecting your car heater venNULYLU NULYLU Heater Ducting Hose Tube Connector 2Pcs 42Mm to 75Mm Plastic Reducer for Car Heater Fittings and Diesel Parking V Plastic material: crafted from high strength plastic, this heater vent outlet connector offers excellent resistance to hGadpiparty Gadpiparty 10pcs PVC Pipe Diameter Reducer and Increaser Adapter for Airflow Tube Pipe Fitting, Smooth Diameter Transiti Material assurance: made from strong, quality pvc, this dust collection reducer delivers durability and performance as aCreate idea Create idea 2Pcs M18x1.5 to M12x1.25 Reducer 304 Stainless Steel Conversion Tube for Car Sensor Water Pipe Suitable for automotive sensor installation (such as oxygen sensor), mechanical connection, water pipe interface and othHALLMERS HALLMERS 12mm to 10mm Brass Straight Barbed Pipe Fitting Connector Plumbing Hose, Barb Tubing Adapter Coupler Reducer Co This is a handy brass barbed fitting commonly used to connect lines for air, water, fuel, oil, and inert gases.John Guest John Guest Acetal Copolymer Tube Fitting Reducer 3/8 Tube OD x 1/2 Stem OD (Pack of 10) HALLMERS HALLMERS 16mm to 8mm Brass Straight Barbed Pipe Fitting Connector Plumbing Hose, Barb Tubing Adapter Coupler Reducer Con This is a handy brass barbed fitting commonly used to connect lines for air, water, fuel, oil, and inert gases.Independently Published Pipes, Tubes, and Hoses in Hydraulic Systems: In the English Units: 6 Hallmers HALLMERS 16mm to 12mm Brass Straight Barbed Pipe Fitting Connector Plumbing Hose, Barb Tubing Adapter Coupler Reducer Co This is a handy brass barbed fitting commonly used to connect lines for air, water, fuel, oil, and inert gases.HAMPPLIES HAMPPLIES 10pcs PVC Duct Reducer Coupling for Vent Pipes with Smooth Diameter Transition, Noise Reducing and Sturdy Airf Effortless installation: the duct reducer fitting features an intuitive structure for quick mounting, simplifying upgraduxcell uxcell Straight Push to Connector Reducer Fitting 8mm to 4mm Quick Release Pneumatic Connector Plastic Union Pipe Tube F 5 Pcs for 8mm to 4mm OD plastic straight tube fitting.ECOPRO VENT 5" to 4" Inch Galvanized Steel Round Duct Reducer - Pipe Fitting Increaser Reducer - Drain, Waste and Vent Conduit Trans Round Ducting Adapter: Converts 5" (4.92") to 4" (3.93") / 125mm Male to 100mm Male SizesLeeQinersw LeeQinersw Ducting Reducer Increaser 4" to 3" Accessories Pipe Fitting for Inline 【Easy to Install】just connect the two ends of the connector with of appropriate sizeYetuow Yetuow Ducting Reducer Increaser 4" to 3" Pipe Fitting for Easily Install 【Material】Ducting Air Tube Increaser Adapter is made of material, lightweight andJohn Guest JOHN GUEST - 5/16"OD TUBE X 3/16" STEM TUBE REDUCER - Reducers (Push-in Fittings, Imperial) - PACK SIZE: 1x5 Adaptors and FittingsJohn Guest John Guest Acetal Copolymer Tube Fitting Reducer 1/4 Tube OD x 3/8 Stem OD (Pack of 10)