Remote Bulb Controller, Regulates Temperature of Air or Liquids in Ducts, Pipes, Tanks and Boilers, 120Vac or 240/277Vac, 0-100 Degree Setpoint Temperature Range, 125 Degree Maximum Operating Temperature, 3-10 Degree Differential Temperature, 1/2"x4 3/16" Copper Bulb, 20' Capillary Length, 1 SPDT Output, Can be Mounted in any Position, Includes Duct Bulb Holder