This push pull valve is designed to use with Pentair Sta-Rite System 2 modular PLDE-series, System 3 SD-series and modular SMD-series pool/spa D.E. filters and also compatible with Pentair Sta-Rite System 3 SS-series pool and spa sand filters. Unique handle design allows easier operation, pin locks valve in filter position. Two-position backwash valves have minimal flow restriction. Measures 7-4/5-inch centerline.