Soothe your baby to rest with the Perfect Calming Center by CoCaLo Baby. Simply place the foam mat underneath your crib mattress, with the battery pack facing outward. Activate the Perfect Calming Center with the press of a button on the remote control. This battery-powered remote control can be activated up to 16 ft. from the foam mat. There are 4 individual functions you can access: Manual or cry-activated Vibrate, play music, or both Play Braham's lullaby or the sound of a gentle heartbeatChoose the volume of the sound or intensity of the vibration. These unique functions will help lull your baby to restful sleep with minimal interruptions. Requires 4 AA batteries and comes with a zipper pocket to hold the battery pack.