An item that does exactly what it says it will, the McAlpine Tee Vent is a valuable addition to any of your bathroom fixtures and fittings.
McAlpine TV2 1½" TeeVent with Multifit
1½" TeeVent domestic appliance connector with non-return valve for use with WM4 trap
For use with WM4 Trap. The Tee Vent, which incorporates a Non-Return Valve, provides an air break and enables the waste system to be sealed. The Tee Vent can be extended away from the Trap by inserting a length of waste pipe between the Fitting and the Trap. Should a blockage occur, the Non-Return Valve prevents flooding.