Fully adjustable to fit your new baby, the Summer Infant Supreme Sleep Positioner is the safe, comfortable crib accessory for newborns that helps you make sure that your baby sleeps on his back in the center of the crib, the precise posture that the American Academy of Pediatrics recommends. An ingenious heartbeat device is included with this soft and breathable fabric-covered foam positioner. It listens for your baby's cries and automatically sounds a soothing heartbeat that gives newborns the reassuring feeling that Mom is close by. You'll always remember to alternate the direction your baby lays when you put her to bed with the TOTS reminding system, helping to prevent Flat Head Syndrome (Plagiocephaly).