Movement Built in movement to very high sound . clear and sweet sound. none battery needed Clockwork music box , none battery needed , just turn the for 3-4 circles , then release , it will play music. minis Size Suitable for handheld, small size ensures portability, you can play music anywheres. Great : beautiful music box, as a for your spouse, lover, relatives or yourself and even for Perfect for friend. Package includes: 1Piece Musical Jewelry Box