Canplas 223285W PVC Backwater Valve with 16-Inch Access Sleeve and ABS Lid， 4-Inch<div style="text-align: left;"><strong>[Product Information]</strong><br><ul><li>Protection against the backflow of sewage and storm water</li><li>Compact， lightweight and easy to install</li><li>All Canplas Backwater valves are socket x socket with all sockets being DWV</li><li>Acme threads provide positive traction and extra strength</li><li>Neoprene O-ring effectively seals valve lid</li></ul></div><img src="http://ecx.images-amazon.com/images/I/31TQrkf4oXL.jpg" noproxy>