Pentair 27001-0054S Posi-Lok Ring Replacement Sta-Rite Pool/Spa D.E. and Cartridge Filter Posi-Lok ring replacement Fits Pentair Sta-Rite PLM and System 2 modular media pool and spa cartridge filter models PLM100, PLM125, PLM150, PLM175, PLM200, PLM300 Also fits Pentair Sta-Rite PLD and System 2 modular pool and spa D.E. filter models PLD50-DE, PLD70-DE, PLDE36-DE, PLDE48-DE, PLDE70-DE Measures 23-3/4-inch length by 5-1/2-inch height by 21-1/4-inch width