Pentair Black O-Ring | Sta-Rite Posi-Flo II Cartridge Filters | WC9-3 Calcium Hardness Prevents pool water evaporation and

Prevents pool water evaporation and heat loss

as earlier blow-molded tank configurations may differ

⚠️ IMPORTANT: Many Maax & Elite Spa Systems Require Two Cartridges

Frequently Asked Questions (FAQs)

3 and 5 Pentair MasterTemp 400LP 400LP O-Ring Kit

Pentair Black O-Ring | Sta-Rite Posi-Flo II Cartridge Filters | WC9-3 Calcium Hardness Prevents pool water evaporation andThe Pentair WC9 3 is the OEM replacement black O ring for Sta Rite Posi Flo II pool and spa cartridge filters, keeping the filter housing sealed and operating at full efficiency. IMPORTANT: LUBRICATION REQUIRED SOLD SEPARATELY Always lubricate this O ring with a silicone based lubricant before installation. We carry the Pentair R172351 Lifeguard Silicone Lubricant the OEM matched product for Pentair equipment. This O ring maintains the pressure seal