O-Rings Compatible with APEC 3.5 Inch O-Rings for APEC Ultimate and Essence Series Reverse Osmosis Water Filters, Version B (6-Pack)

6-pack of O-ring gasket seals. Compatible with APEC ESSENCE RO systems purchased after June, 2013. Also Compatible with ULTIMATE RO systems purchased after May 2015. ⚠️ Not Compatible with APEC ESSENCE RO systems purchased before June, 2013 and ULTIMATE RO systems purchased before May, 2015. Please reference your user manual to determine correct model ⚠️ Compatible with APEC Reverse Osmosis Models: RO-45, RO-90, RO-PERM, RO-PUMP, ROES-50, ROES-PH75, ROES-UV75, ROES-UV75-55 and ROES-PHUV75. Replacing O-rings can return your filtering system back to peak performance. Outside Diameter: 3 1/2 inches. The brand names and logos are the registered trademarks of their respective owners. Any use of the brand name or model designation for this product is made solely for purposes of demonstrating compatibility. Packaging may vary.