The RK12-QT Quick Test Backflow Test Fittings are compatible with the 2-1/2” - 4” Backflow Preventers. Repair Kit components include three 1/2” brass Quick Test Fittings, three 1/4” brass Test Fittings, and tear-resistant O-Rings. 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.