1.New Upgrade：Compared with the previous backup valve , we have upgraded the shell material, Made of crack-resistant polymer blend,which is more wear-resistant than the previous product, will not be easily damaged, and has twice the life span. 2. G53 Gear Mechanism:Made of friction-resistant and stable POM material. Pom has a very low coefficient of friction and good geometric stability, especially suitable for the manufacture of gears and bearings, this material is more able to withstand high water pressure operation. But if there is too much sand, the gear will be stuck. At this point, you need to remove the grinding wheel to clean the sand to continue working. 3.The back up valve Compatible with Zodiac Polaris models 180, 380, 280, 480 PRO, 3900 S.
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