The QT Quick Test Fittings Set is compatible with the 1/4” - 2”, 2-1/2” - 4”, and 6” - 10” Backflow Preventers. Quick Test Fittings facilitate the connection of a Differential Pressure Test Gauge. Featuring an integral O-ring and hand-tight installation, Quick Test Fittings eliminate the need for wrenches and Teflon® tape, saving the tester valuable time and money on materials. Sold conveniently in a 3-pack, each QT-SET contains 3 of each fitting size (1/4", 1/2" and 3/4") and 3 spare O-rings per size, all packaged in an easy carry case