This is the baby crib mobile that detects whether an infant is awake or drifting to sleep, then changes its music, movement and lights to match. For a baby freshly put to bed, this device plays gentle music and projects soft lights on the swaying paddles above. Sensors detect when the sleepy baby's movements begin to slow, and the device adjusts the sound and light display to lull the child completely asleep. It then shuts itself off when the baby is asleep at last. If the child wakes, sensors activate dim lights to keep the baby calm. For parents who want to wake their infants gently, this mobile can be set to engage softly after four, six, or eight hours of rest. Requires four C batteries. For infants up to 5 months. 14" H x 9" W x 9" D. (3 lbs.)