JoyTube Plastic Hose Barb Reducer Pipe fittings, 1/4" to 3/16" Hose ID Connectors Joint Splicer Mender Adapter Union Boat Water Air Aquarium O2 Fuel ...
1/2" Tube O.D. x 1/4" MPT, Male Connector Molded Compression Tube Fittings - 1568X8X4 - Hi-Line Inc.