The Pro-Temp pt-100 Commercial Thermometer is the Highest in accuracy. With all the features of a commercial-grade thermometer, You're assured an accurate reading every time to 1 degree C. The Pro-Temp is water and dust resistant, as well as shock-resistant to multiple drops on a concrete floor-a must in a fast-paced commercial kitchen environment. Instant measurement of temperatures from -40F to 450F or 40C-230C within three seconds. Reverse LCD, auto on/off features, handy cooking chart and the ability to fold into a compact unit-They anticipated the demands of the professional chef. Each unit has factory certification - NSF approved for professional use, certificate included guarantees performance and accuracy to NIST standards. There is no need for a special battery it uses Three AAA batteries included.