Check the listing for details. Polaris 180 280 360 380 G57 Collar Ring Replacement Part for G52 Back-Up Valve. Condition: New. Listed at 12.95 USD. NEW Polaris G57 Replacement Collar Ring Fits the G52 Back-up Valve For use with the Polaris 180, 280, 360, 380 and 3900 model pool cleaners which use the G-52 acorn style design back-up valve. This replacement Polaris back-up valve Collar ring (G-57) is the current replacement collar for the G-52 complete backup valve. * If all you need is the collar due to a cracked or damaged part. Then this is the part for you. Save some buck$ here at our ebay pool store! (1) Collar Ring ORIGINAL Replacement part # G57/G-57 Assembly Tip: Make sure that your current o ring on the case kit is in good shape and is not damaged. (replace if damaged)Make sure o ring around the case kit shell is lubed with o ring grease.When assembling make sure that the notches on both sides of the two halves of the case kit meet up with each other. Once haves are together align the threaded collar onto the threads of the case kit and slowly thread together.Make sure that the threads do not cross thread each other. We carry a wide variety of automatic cleaner parts! Please click here for more Polaris cleaner parts and tune-up Kits! Be sure to add me to your favorites list!