Quick-response sensor External probe range is –58 to 158°F and –50 to 70°C (OUT reading). Ambient internal probe range is 32 to 122°F and 0 to 50°C (IN reading). Resolution is 1° and accuracy is ±1°C. Humidity range is 25 to 95%, resolution is 1% RH, and accuracy is ±2% RH mid-range to ±4% RH elsewhere. Display is updated once per second. Minimum and maximum memories may be displayed or cleared at any time with the touch of a button. They permit monitoring conditions overnight, on weekends, or for any time period. Jumbo 1-1/8-inch display may be read from as far away as 35 feet. Traceable® Certificate Multi-point calibration on an individually-numbered Traceable® Certificate which assures accuracy from our ISO/IEC 17025:2005 (1750.01) calibration laboratory accredited by A2LA. It indicates traceability of measurements to the SI units through NIST or other recognized national measurement institutes (NMI) that are signatories to the CIPM Mutual Recognition Agreement. Fulfills CLIA requirements Meets federal requirements for CLIA specification 493.1207 for monitoring temperature and humidity. Self-contained, stable, accurate unit requires no adjustment or maintenance. Case is chemical- and shock-resistant ABS plastic. Supplied with flip-open stand, wall mount, and AAA batteries. Size is 4-1/4 x 4 x 3/4 inches. Weight is 5-3/8 ounces. Replacement battery Cat. No. 1105.