An item that does exactly what it says it will, the McAlpine Air Admittance Valve is a valuable addition to any of your bathroom fixtures and fittings.
McAlpine VP50P Ventapipe 50 Air Admittance Valve
Dual fit synthetic rubber finger seal outlet for 3" or 4" soil pipe
For 4"/110mm soil pipe push over rubber seal, for 3"/75mm soil pipe push in to rubber seal
Complies with standard: BS EN 12380:2005
For use in above ground drainage systems to provide a means of ventilation under conditions of reduced pressure when ventilating pipes are terminated inside buildings in accordance with BS EN 12056-2:2000