Pentair 27001-0022 1-1/2-Inch NPT Plug Replacement Sta-Rite Pool and Spa Filter Plug replacement Fits Pentair Sta-Rite PLM, System 2 and 3 modular media cartridge filter models S7M120, S7M400, S8M150, S8M500, PLM100, PLM125, PLM150, PLM175, PLM200, PLM300 Also fits Pentair Sta-Rite PLD, System 2 and 3 modular media pool/spa D.E. filter models PLD50-DE, PLD70-DE, PLDE36-DE, PLDE48-DE, PLDE70-DE, S7D75, S8D110 Also compatible with Pentair Sta-Rite System 3 pool and spa sand filter models S7S50, S8S70 Comes with 1-1/2-inch NPT; measures 2-1/8-inch length by 1-1/4-inch height by 2-1/8-inch width