Honeywell High Limit Aquastat Relay, 120Vac, 180-240 Degree High Limit Operating Range, 15 Degree Fixed Differential Temperature, 1 1/2″-3″ Insulation Depth, 0-95% RH Operating Humidity Range, 4 1/2″ Capillary Length, SPST High Limit and Circulator Switching, Vertical Mount, Includes 50va Tansformer and Heat Conductive Compound