The class 9037 Type H switches are attached to the tank by means of a 2-1/2 in bushing. An external pointer indicates the float position within the tank when the unit is mounted. Switches come complete with stainless steel float and rod. A nitrile rubber seal, such as a Buna-N quad ring seal, is used between the float rod and the sealing connector. Normal application is at atmospheric pressure. Where higher pressures are encountered, the available FKM seal allows the switch to withstand tank pressures up to 50 psi at ambient temperatures up to 220 deg F. Occasional replacement of the quad ring seal may be necessary.