These rugged PKI 5165 Thermal Imaging Monocular/ Binocular devices are used for the observation and terrain orientation under poor weather conditions like smog, mist. For longer observation periods, two individual devices can be assembled to a binocular system in order not to overstrain the eyes. The max. visual range to recognize a person is approx. 500m. by the PKI 5165 Thermal Imaging Monocular/ Binocular.