This Angelcare movement only monitor AC300 is ideal for parents who already have sound monitor or have twins and require separate movement monitors. A SensorPad is included which will monitor your baby's movements, even the slightest breathing movements. An alarm will sound if no movement is detected after 20 seconds. The Tic function allows you to 'hear' that movement is being detected. There is a low battery indicator which will last 3 to 4 months. 2xAA batteries are included with this monitor. Age range birth+.