Pentair PKG 188 Union Kit is an adapter package replacement consisting 2 pcs 2” half union which are designed to use with Pentair Sta-Rite System 3 Modular Media SM-Series pool and spa inground filters model S7M120, S7M400, S8M150, S8M500. It also fits Pentair Sta-Rite System 2 Modular D.E. PLDE-Series pool and spa inground filters model LDE36, PLDE70. These half union adapters are also compatible with Pentair Sta-Rite System 3 Modular D.E. filters SMD-Series, Max-E-Therm, MasterTemp, Max-E-Pro pumps, Dyna-Pro pumps, Dyna-WaveParts-Paks, MasterTemp, IntelliPro VS 3050 Pump, Dyna-Glas/Dyna-Max series, Dyna-Pro/Dyno-Pro E pumps, Dyna-Wave series pool and spa inground filters.