This is a 52mm Mechanical gauge, with Black Bezel and Black dial. Range 40 -120C, Capillary length - 6 feet, End fitment- 5/8"-18 UNF with 1/2" Adapter. This gauge has a built-in electrical switch for tripping alarms and/or shutdown devices. This gauge has a sealed capillary tube and a sensing bulb. When subjected to heat, the liquid in the sensing bulb changes to vapor creating pressure which translates this vapor pressure into a mechanical gauge reading. The gauge pointer acts as a temperature indicator and as a one switch pole which completes a circuit when it touches the adjustable limit contact. The preset level can be changed using a 1.6mm Allen key.