Three-Pack 3.5 Inch O-Ring Seals for RO Housings ✔️ Three O-rings per pack, 3.5 inch (89 mm) OD, fits 10 inch housings Designed for 3.5 inch OD filter housings used in home reverse osmosis systems, these o-rings provide a reliable, leak-proof seal. Compatible with Essence and Ultimate RO setups and other 10" standard housings. ✅ 3.5 inch (89 mm) OD nitrile O-rings, flexible and abrasion-resistant ✅ Fits 10 inch standard housings and Essence and Ultimate RO systems ✅ Pack of 3 in black; replace every 1-2 years with a food-grade lubricant 💡 What is a common use for O-ring seals in home RO systems? Leak-proof seal between lid and housing to prevent drips Easy replacement to maintain pressure and filtration integrity Use a food-grade lubricant for best performance during installation