The CRAFTSMAN Multi-Room Monitor provides you useful multi area monitoring capabilities. It includes a 4-zone digital display and 3indoor/outdoor wireless temperature and humidity sensors. This system features the ability to measure temperature and humidity in up to four locations in and around your home. A premium display with a built-in digital thermometer and humidity gauge lets you view， at a glance， environmental information to help keep your family comfortable while protecting your residence and possessions. Each sensor requires 2 AA alkaline or lithium batteries (not included)， and the display requires 3 AA alkaline batteries (not included). The multi area temperature and humidity station comes with a one-year limited warranty.