Valterra Products, LLC, has been a leading supplier of brand name product lines to the RV, pool & spa, and plumbing industries. Here you will find Valterra check valves which are available with a swing (no spring) or swing/spring combination. All springs have a 1/2 lb tension. Sizes for the check valves range from 1/2 inch up to 6 inches in size. You have the ability to select check valves that are clear which enable you to see the water as it flows through the valve or you may select the traditional solid color (white). There are two fitting connections of slip x slip and FPT x FPT.