PREMIUM QUALITY- 1. This G52 Backup Valve is designed to return the cleaner to the corner or edge of the pool when the pool cleaner gets stuck on an obstacle. 2. Compared with the previous replacement valve, the new G52 is upgraded to G54 material, which is made of a crack-resistant polymer blend, and the included G53 gear has also been reinforced. The service life is lined and it is more wear-resistant than the previous product. PERFECT FIT- The robot pool cleaner G52 relief valve replacement kit is exactly compatible with Zodiac Polaris 180 models , 280, 380, 480 PRO, 3900 Sport, Vac-Sweep 380, Vac-Sweep 280, 280TankTrax. FIXED SITUATIONS- When the pool cleaner is entangled by obstacles or edges, it will is difficult to roll over or float on the surface of the pool water, or even if the relief valve is still open and water is no longer spraying from the nozzle, you should consider checking or repairing it. replace, covienapp updated Polaris 180 280 380 spare part Valve G52 solves this problem. EASY TO USE - No assembly required. The G52 relief valve is ready to install, just connect the fittings and pipes firmly to work. And opens every 3 minutes for 30 seconds to remove the cleaner by changing its cleaning direction. This valve is also capable of pulling the unit out of tight spots if it gets stuck. Salt water pools are also suitable.