[Quiet Operation]water hammer noise occurs when discharged water slams against the sump pump check valve baffle; The sump pump check valve has a baffle that helps water hammer noise caused by the check valve;perfect bedrooms, basements, or any area that needs noise reduction [Valve Body Visibility]the transparent structure makes it easy to confirm whether the flow inside the sump pump check valve 1.5 inches is smooth; Clear visibility ensures peace of mind and allows you to easily monitor your sump system [Easy to Install]designed to fit1.5inch gauge 40 pipe, the sump pump check valve easily integrates into your existing plumbing setup; Fits 5-1/ 8inch clearance [Prevents Water Backflow] the sump pump check valve quite has a one way flow mechanism that allows water to flow out of the pump but avoids water backflow; Check valves to prevent water from backing up from the drain pipe into the sump [ Resistance]the sump pump check valve quite is equipped with clamp ; These components resist and rust, ensuring leak free performance Please note: the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Colour:Black Material:ABS Package Contents: 2x check valves 1x screwdriver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.