The quick action flapper allows unrestricted uni-directional flow. Elastomeric gasket in the flapper ensures a watertight seal. Flapper can be easily removed and replaced if required. Threaded access cap is designed for hand tightening. Access cap neoprene gasket provides a positive seal. Valve hub outlets fit 2", 3", 4" or 6" DWV pipe and may be adapted to 2", 3", 4" or 6" sewer and drain pipe with NDS DWV to Sewer & Drain Adapters. Lightweight, easy to install. Horizontal installation required, with arrows on top of the valve hub pointing in the direction of the flow of water. Access riser with cover offers a simple, economical access to the valve for inspection and maintenance. The riser may be cut to the desired length.