Polypipe 40mm Nuflo Washing Machine Half Trap 75mm Seal with Adapter is used to provide a water seal between the waste water pipe and the internal environment of the room. It prevents any foul odours from the drains from re-entering the room. The trap uses an easy grip compression nut, tapered rubber seal, rubber 'O' ring and a slip ring to give a secure watertight seal. The adapter allows for the connection of the hose running from the appliance.