The Basement Watchdog Klunkless Check Valve is here to put an end to the annoying clunking sound that occurs when your sump pump turns off. Its patented silencing air chamber effectively absorbs the shock, ensuring a peaceful environment. Effortlessly install it on both 1-1/4" and 1-1/2" pipes without the hassle of gluing (pipes not included). The airtight chamber prevents water entry, offering reliable performance. Comes with a 1-year limited warranty for your peace of mind.