2 " Dia., ABS Plastic, Polystyrene, Connector: PVC, White Finish, MINI-VENT(R)Mfr #: 20301 Compact air admittance valve with PVC adapter Ideal for a single fixture or group of fixtures; capacity of 160 DFUs (drain fixture units) on a branch and 24 DFUs on a stack Creates ventilation that prevents the loss of water seals in traps; uses gravity to automatically close seal and prevent circulation of unpleasant bathroom or drain odors Fits 1 1 2 and 2 inch piping; temperature rating of 40F to 150F ( 40C to 65. 6C); complies to ANSI