The McAlpine WM3V is a plumbing trap designed for use with standpipe waste systems. It is an anti-syphon (Silentrap) standpipe trap, which means it is designed to prevent the backflow of wastewater from the pipework and prevent airlocks in the system. The trap has a 75mm water seal to prevent foul odours from entering the room, and a 1.5" multifit outlet for easy connection to standard pipework. Unlike other traps that connect directly to an appliance, the WM3V connects to a standpipe waste system, which is a vertical pipe that extends from the floor or wall. The anti-syphon feature of the WM3V trap prevents the siphoning of water from the trap, which can lead to airlocks and the release of unpleasant odours. This feature ensures that the trap remains full of water, creating an effective barrier to prevent the backflow of wastewater. The WM3V is designed as a standpipe trap, meaning that it is designed to be installed on top of a vertical standpipe waste system. The trap is connected to the standpipe by a rubber seal, creating a watertight connection that prevents any leaks or smells from escaping. Overall, the McAlpine WM3V trap is a reliable and easy-to-install solution for standpipe waste systems. Its anti-syphon feature and 75mm water seal make it an effective barrier against backflow and unpleasant odours. Its 1.5" multifit outlet also makes it easy to connect to standard pipework. For use with WM3 Trap to cap off standpipe McAlpine WM3V 1.5" Standpipe Trap with Anti-Syphon (Silentrap) in White