Compatible model: G52 valves compatible with Zodiac Polaris 180, 280, 380, 480 PRO, 3900 Sport, Vac-Sweep 380, Vac-Sweep 280, 280 TankTrax models. Upgraded version: Compared to the previous valve, our G52 valve replacement kit for Polaris has improved shell material, crack-resistant polymer construction, won't be easily damaged, and has twice the service life. /p> G53 Mechanism: Made of friction-resistant and stable POM material. Pompom has a very low coefficient of friction and good geometric stability, especially suitable for making gears and bearings, this material is more able to withstand high water pressure. Function: the upgraded version will solve the problem when your pool cleaner gets stuck on an obstacle, although your relief valve is still open, water will no longer spray from the nozzle, and will keep the water out. Content: 1 valve replacement kit from G52.;