Compatible with for intelliChlor IC15, IC20, IC40, IC60, and ichlor salt chlorine generators. The prevents leaks and poorly filtered pool backwash lines to improve the performance of your pool valves and filtration systems 521147 o-rings seal the cell union fittings on each end of the system and are also part . Ensures a secure, leak-proof seal on union connections to maintain system efficiency and safety Critical for sealing union joints to avoid water leaks, salt loss, or gas escape. Safeguards chlorinator's internal components from moisture and debris, reducing wear and extending the system's lifespan 521147 union o-ring is made of premium rubber, resist from saltwater, chlorine, UV rays, and extreme temperatures. Prevents cracking, swelling, or degradation for reliable, long-term performance Color:Black Material:Rubber Package Contents: 12 * 521147 Union O-Ring Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.