Operating Environment: Ambient temperature range: -40 ℃ ~ 80 ℃ (can not be plunged, orelse this will cause condensation) Ambient humidity range: 10% ~ 90% (no condensation) The main function parameters: Power voltage: DC/AC 12V to 24V Power consumption: 30mA (DC12V Power) Temperature measurement display range: -55 ° C to +125 ° C / -67 ° F ~ +257 ° F Display Resolution: 0.1 ° C Measurement accuracy: 10 ℃ ~ 40 ℃: ± 0.2 ° C ; -10 ° C ~ + 85 ° C: ± 0.5 ° Measuring cycle: typical 3 times / sec or faster Transmission distance: matching 1 meter DS18B20 , maximum transmit 200 meters without loss of accuracy . Installation size: Panel Dimensions: 79 x 42mm Cut-out Dimensions: 76 × 39.5mm Package: 1 x LED Digital Thermometer 1 x DS18B20 Digital Thermal probe/sensor