Glentronics, Inc. KCV 1-1/4 Inch to 1-1/2 Inch Basement Watchdog Klunkless Check Valve Eliminates the irritating "clunk" when sump pumps turn off Patented silencing air chamber absorbs the shock Easily installed on both 1-1/4-Inch and 1-1/2-Inch pipes Includes stainless steel hose clamps Designed for years of use