Honeywell T678A1437?áRemote 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 Degree Fixed Differential Temperature, 3-10 Degree Interstage Differential Temperature, 1/2"x4 3/16" Copper Bulb, 5' Capillary Length, 2 SPDT Output, Can be Mounted in any Position

T678A1437 is identical to T678A1437/U