The PINPOINT Wireless Thermometer can accept a maximum of 4 remote sensors, thus expanding the monitoring capability to 4 different locations to be displayed on the same PINPOINT Temperature Display Monitor (2-AAA batteries are required, but not included, for the meter and 2-AAA are required for each remote sensor). AC operation is not an option here because of the efficient power management of the electronics. Battery life is approximately 2 years. Given proper care, the PINPOINT Wireless Thermometer™ should last a lifetime. Remote sensors can transmit temperature signals as far as 100 feet (30 Meters) in optimum conditions. The monitor and remote sensor are powered by two AAA batteries each. Monitor accepts up to four remote temperature sensors.