A thermal sensor that is durable, stable and accurate up to 300 yards. The built-in red laser and infrared lasers help pinpoint heat sources at night. False readings are eliminated with the 64 different sensitivity settings. The HeatSeeker works by detecting heat sources and motion of heat to help find game or humans. Temperatures are read as infrared lightwaves which appear on the digital bar graph display and are pinpointed by the built-in red laser and infrared laser. Audio squelches that correlate with the detection of heat can be heard through the earphone. Weight with Battery: 8.25oz Length: 7" Diameter: 1.75" at handle Battery: 9V Alkaline