Wireless indoor and outdoor comfort weather station. Reads and records indoor and outdoor temperatures and has temperature and humidity trend indicators. Indoor temperature range is 32 degree F/122 degree F and 0 degree C/50 degree C. Outdoor temperature range is -4 degree F/140 degree F and -20 degree C/60 degree C (lithium batteries) -40 degree F/140 degree F and -40 degree C/60 degree C (lithium batteries). Displays clock and calendar function. Wireless remote sensor has a 200 ft range.