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 upgraded shell material, crack-resistant polymer construction, not easily damaged, and has twice as muchLifespan. G53 mechanics: Made of friction-resistant and stable POM material. The bobble has a very low coefficient of friction and good dimensional stability. This material is particularly suitable for the production of gears and bearingscan withstand high water pressure better. Function: The upgraded version solves the problem when your pool cleaner gets stuck on an obstacle even though your emergency valve is still open, water stops spraying from the nozzle and the water stays out. Contents: 1 G52 valve replacement kit. Compatible Model: Fit for Polaris 180 280 380 480 PRO 3900 Sport, Vac Sweep 380, Vac Sweep 280, 280 TankTrax. Made of abrasion-resistant and stable POM material. Pom has a very low coefficient of friction and good geometric stability, this material is better able to withstand high water pressure operations. Function The updated version solves the problem when your pool cleaner is stuck on an obstacle even though your relief valve is still open, no longer sprays water from the nozzle and prevents water from entering. G53 gear material: POM material. Solve problem: When the cleaning robot is stuck on obstacles or edges and it is difficult to turn around, Or even if the emergency valve is still open, no more water comes out of the nozzle, Then it's time to consider a review or exchange.