The Angelcare Movement Monitor is a great addition to your existing sound-monitoring system or can be used in conjunction with a Sound and Movement Monitor giving you the ability to monitor more than one baby. We do not recommend using this monitor only unless you live in a very small space or your baby sleeps in the same room you do. We recommend that use is combined with a monitor that detects sound.Movement monitoring is thorough and simple with this unit which consists of a high quality Sensor Pad that fits under the mattress and is designed to detect movements with great sensitivity. If no movement is detected for 20 seconds an alarm is sounded on the included parent unit. Track your baby and give yourself peace of mind. The parent unit operates on two AA batteries.About AngelcareBased in Montreal and first founded in 1997 Angelcare is committed to producing safe high quality nursery monitors that ensure your baby's safety and make your job as a parent a little easier. Angelcare monitors were developed specifically to combine the best of both worlds - sound and motion monitoring - to bring you a single product that can give you peace of mind with less hassle. After extensive research and development Angelcare monitors have become top sellers in over 40 countries worldwide.