Add on wireless 180 degree motion sensor can be programmed to operate during the daytime only (DAY ONLY) or both day and night (DAY/NIGHT). The adjustable RANGE control increases and decreases the sensitivity of the sensor to detect movement. ON-TIME control determines the amount of time that all motion must be stopped before the sensor will activate the chime again. Motion must be stopped for 10 seconds before reactivation. Can be set for 1 or 5 minutes before reactivation. Requires 2 - AAA and one 1.5V battery, not included.