【Great Compatibility】 385318032 Vacuum Tank Switch Kit is compatible with Sealand / Dometic 729100 Vacuum Pump Kit. Compatible With Vacuum Tank Models: 317729100, 317729200, 317729400, 317324002, 385311660. Also suitable for the S pump and separate accumulator tank. Large O-ring that seals the switch flange to the tank is included. 【Perfect Design】 The resistance of coil is set to 8 to 10 inches. When the vacuum is being pulled into this chamber that diaphragm is pulled inward, pulling this way from trigger so that will turn the pump off. If the system is building enough vacuum but your switch is not responding to turn the pump off, maybe it's time to upgrade your Vacuum Tank Switch. .
eBay