Replacement O Ring Set for 3.5 Inch RO Housings 3-Pack ✔️ 3-Pack O-rings, 3.5 in OD, NSF-certified for 10 in housings This O-ring kit is designed for standard 3.5 inch OD RO filter housings and is a solid maintenance option for drinking-water systems. It fits APEC Essence and Ultimate RO units and works with most 10 inch standard filter housings. The gaskets are made from NSF-compliant materials for safe contact with potable water. ✅ Diameter 3.5 in OD (89 mm) to fit standard 10 in housings ✅ NSF-compliant materials for safe drinking-water use ✅ Lightweight and easy to install, compatible with common food-grade lubricants ✅ Replace every 1-2 years to maintain a reliable seal 💡 What is a gasket O-ring set for RO filter housings used for? - replacement O-ring set for 3.5 inch RO housings helps seal the housing cap and body - fits 10 inch standard housings and APEC Essence/Ultimate systems - quick, tool-free installation for maintenance and leak prevention