ACU-RITE #00606 is a wireless thermometer designed to accurately measure both indoor and outdoor temperatures. The device consists of two units: a main unit and a wireless sensor. The wireless sensor is designed to be placed outdoors to measure the outside temperature, while the main unit is designed to be placed indoors to display both the indoor and outdoor temperatures. Both units require batteries to operate, with the main unit using two AAA batteries and the wireless sensor using two AA batteries.