For use with Omni whole house filters Nos.OB1, OB5, R12, and R14; and Omni under-sink water filters Nos.CBF20, SFM2, UC2. CBF1, CBF3, OT32, OB3, and RO2000. Will also fit Nos.BC1, TC3, UC2, U400. U500, U600, U700, Omni Super, and Total 2. If your unit uses blue o-ring, replaces Total Plus, Omni Regular and Omni Deluxe o-rings. Bagged.