John Guest Speedfit 12mm X 1/2" Female Adaptor BSP - CM451214FS (Pack of 10)John Guest push fit acetal female adaptor (BSP thread) fitting connects metric sized pipework to a BSP type fitting. Fast and simple to install, John Guest push fit fittings create an instant push fit connection and leak tight seal without the need for tools, hot works or sealing agents. The unique collet locking design firmly and securely holds the pipe in place without deforming the pipe or restricting flow. Fittings are corrosion resistant and