PRODUCT DESCRIPTION Instantaneous Rubber Washers are fitted to a variety of firefighting fittings in order to create a water-tight seal to ensure outlets have maximum water pressure when you need it most. The 2 ½" (64mm) rubber washer will fit standpipe bases, dry riser landing valves and a wide variety of other equipment. Especially where outlets are regularly used, the instantaneous washers quite often require replacement during dry riser maintenance visits as, like all rubber washers, they will eventually perish. Manufactured for Vigil Products of rubber nitrile for guaranteed quality.