1236-17-1 Cooper Bimetal Pocket Thermometer 1" Dial 5" Stem With Adjustment Sheath 25°F-125°F: 1" dial 5" stem. All 1” Pocket-tests are field adjustable and include a red, protective sheath with calibration wrench made with anti-microbial plastic and pocket clip.. The anti-microbial additive in the ABS plastic sheath inhibits the growth of bacteria on the unit. It does not protect users or others against bacteria.