The Home Monitoring Station with 3 Sensors includes a color-coded 4-zone digital display, a Wireless Temperature and Humidity sensor, and two Indoor Room Sensors. This system features the ability to measure temperature and humidity in one outdoor and three indoor locations. A great option for an indoor/outdoor thermometer/humidity gauge, it lets you view at-a-glance information to keep your family comfortable, while protecting your residence and its valuable contents. The base display requires three AA batteries, the two room sensors require two AAA batteries each and the remote sensor requires two AA batteries (no batteries included).