"Wireless rain gauges are the new era. No more running outside to read and empty collection devices. With these digital devices, everything you want to know is available. Hourly, daily, monthly or annual histories digital or graphical. (Graphic display is particularly good on this model.) Also outdoor and indoor temperatures, and rainfall alarm. Just place the collector funnel outdoors in a suitable and appropriate place up to a maximum 100m from display unit. Powered by 2 x 'AA’ batteries in base station and 2 x 'AA’ in transmitter unit. (Batteries not supplied.) Quality instrument made in Germany."