This Etekcity(R) non-contact IR temperature gun is easy to operate. It turns on and begins reading the temperature with one press of the trigger. Clear text displays the measured temperature in either Celsius or Fahrenheit. A laser light aids in aiming, and can be turned on or off. In addition, the readout display features a backlight which can be turned on if needed. 12:1 High distance spot ratio. This means you may measure the temp of a smaller area at the same distance compared to other 8:1 thermometers, thus the readings are much more accurate. Features 1. Laser targeting system for more precise aiming. 2. Greater distance-spot ratio offers accurate results at longer distances. 3. Safely measure hazardous or inaccessible objects. 4. Standard 9V battery offers 12 hours of cumulative use. 5. Auto-shutoff after 15 seconds. Temperature range: -50550 (-581022). Accuracy: +/-2% or 2. Distance spot ratio: 12:1. Emissivity adjustable: 0.95(fixed). Response time and wavelength: 500ms and (5-14)um. Repeatability: +/-1% or+/-1. Resolution: 0.1 or 0.1. Storage temperature: -20-50 (-4-122). Operating temperature: 0-50 (50-122). The measuring surface is about 2cm below the infrared aiming point. 2. When the temperature is beyond measuring range, the LCD will display HI and LO. Measure below-zero and super-hot temperatures. Red laser pointer for precise aiming. Distance Spot Ratio 12:1. Engineered to high precision standards. Auto shutoff in 15 seconds. Powered by one standard 9V battery. Continuous 12 hours battery life. FDA, FCC, CE, ROHS approved.