O-Ring used on the Following Pentair Products: Sta-Rite PRC Aboveground Filter Systems Sta-Rite PRD Filter Systems Sta-Rite System 2 Modular Media Filters Sta-Rite Posi-Flo II Cartridge Filters Sta-Rite Separation Tanks Sta-Rite Max-E-Pro Series Pumps Sta-Rite Max-Glas / Dura-Glas Pumps Sta-Rite Max-Glas II / Dura-Glas II Pumps Sta-Rite Dyna-Glas / Dyna-Max Pumps Sta-Rite Dyna-Jet Pumps