Therm-O-Disc 59T4200, Thermastat Surface Mount Aquastat 120 to 180 F This is the Aquastat that comes on the Back of the Shaver Outdoor Furnace Therm-O Disc - 59T 4200 Thermostat lower Surface Mount Aquastat 120 to 180 F 59T 4200 Therm-o-Disc Manual Reset,120VAC