Honeywell Aquastat Relay, 120Vac, 120-240 Degree High Limit Operating Range, 8 Degree Fixed Differential, 1 1/2″-3″ Insualtion, 0-95% RH Operating Humidity Range, 4 1/2″ Capillary Length, SPST High Limit and Circulator Switching, Horizontal or Vertical Mount