SPECIFICATIONS:
- Outside Diameter: 17 1/2"
- Inside Diameter: 15 1/2"
- Buttress thread on the inside marked with "locked" and "remove" arrows
- 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