The temperature can be detected within 5cm (2 inch) measurement distance. Designed with the latest thermopile sensor technology, to allow infrared laser thermometer gun to provide the highest accuracy up to ±1.5%. Improve the accuracy of their thermometer gun by adjusting the emissivity from 0.1-1.0 according to the surface material being measured. This forehead thermometer is great for kids or adults. Battery is not included.