Honeywell High Limit and Circulator Aquastat Controller, 10 Degree High Limit Differential, 10-25 Degree Low Limit Differential, 1 1/2″ Insulation Depth, SPST Switch, Horizontal Mounting, 130-240 Degree High Limit Operating Range, 110-220 Degree Low Limit Operating Range, 0-95% RH Operating Humidity Range