Inexpensive refrigerator thermometer switchable range is from 14.2 to 131.0ºF and -9.9 to 55.0ºC with a resolution of 0.1°. Accuracy is ±1ºC in the range of 5 to 25°C and ±1.5ºC outside range. Ultra™ model accuracy is ±0.5°C at tested points. Always-hold™ secure suction cup on the back allows the unit to be located anywhere inside the refrigerator; also supplied with place-anywhere Velcro®. Display updates every 30 seconds. This allows capturing a reading without any effect from an open refrigerator door. Wide range of the thermometer also makes it an ideal unit to monitor temperatures in storerooms, labs, offices, hoods, and cabinets. Traceable to NIST for accuracy To assure accuracy an individually serial-numbered Traceable® Certificate is provided from our ISO 17025 calibration laboratory accredited by A2LA. It indicates traceability to standards provided by NIST (National Institute of Standards and Technology). Easy-view, see-through-display LCD digit height is 1\/2-inch. Supplied with long-life 1.5-volt silver-oxide battery. Size is 1 x 2-1\/2 x 3\/8 inches. Weight is 1\/2 ounce. Replacement battery Cat. No. 1102.