Our Premium Quality Bi-Metal Thermometer. This MoreBeer! thermometer features a super sensitive bimetallic helical coil suspended from a copper coated bushing fixed in the stem. This superior design provides a faster response to temperature changes and assures more accurate readings. What does this mean- You don't have to tap the gauge with your finger as much. Accurate to 1% of the total range, these thermometers also feature a polished 3" 304 stainless steel housing, a hermetically sealed water proof case, glass face, external calibration via 1/16" Allen screw, and a unique anti-parallax dial that provides for easy reading. The reading is actually taken from the last 2.5" of the probe. To calibrate properly the manufacturer recommends at 150F. The range is dual scale, 20-240 fahrenheit and -20 to 120 degrees Celsius. The back connection is 1/2" MPT while the stem is 1/4" stainless steel. Manufactured by Tel-Tru.