The IR 516-A is a compact biocular thermal imager. Offering 384x288 resolution combined with an 80mm Germanium lens, the unit has a man-sized detection range of up to 1920m. Its rugged design is IP67 rated. The binocular design allows more comfortable extended observation times. All Guide Infrared thermal imagers feature a 50Hz image refresh rate that gives real time imaging. Other systems use a <9Hz system that means you will see latency or image lag in the image, especially when you are in motion (vehicle, boat etc) or you are tracking a moving object.