Honeywell High Limit Aquastat Controller, 100-180 Degree Operating Temperature Range, 3/8″ Bulb Size, 54″ Capillary Length, SPST, Contacts Break on Temperature Rise 190 Degree Energy Cutoff Temperature, 5 Degree Fixed Controller Differential, 20 Degree Energy Cutoff Switch Differential, Includes Two Zinc PLated Wells and One Well Clamp