Dixon H33BU Ductile Iron Series Q Pipe and Welding Fitting, Quick Release Coupling with Buna-N Gasket, 3" Size x 3-1/2" Pipe OD Quick release couplings are specially designed for applications requiring a quick connection and/or disconnection of a pipe joint A locking pin through the handle prevents accidental opening of the coupling Maximum end load: 2886 Ductile iron body with zinc plating and steel safety clip Interchangeable with: Victaulic's #78, Grinnell's #7003