Feature:1. Easy Operation: The sound power of this music box movement is from spring, use the key to turn the spring tightly, then release and the music will be playing.2. Therapeutic Function: This windup musical movement features therapeutic function for kids and adults, watching the little gears move, and listening to the music, which in itself is soothing to the ears.3. Music Box DIY: This clockwork music box movement can be installed in paper box, wooden box, glass box, plastic box and metal box, then you can create your personalized music box.4. Durable Material: This musical box movement is made of premium alloy material, which is sturdy and highly durable.5. Perfect Gift: This musical mechanism movement produces the sound of "Castle in the Sky", it is also a perfect and meaningful gift for yourself and your friends.Specification:Item Type: Music Box MovementMaterial: Alloy Application: Suitable for Music Box Making, Gift Making, EtcMovement Size: Approx. 5 x 4.6 x 3.5cm / 2.0 x 1.8 x 1.4in (Excluding Mushroom Nail) ( Manual Measurement, Slight Error May Exist )Mushroom Nail Size: Approx. 2.4 x 2.4 x 0.8cm / 0.9 x 0.9 x 0.3in ( Manual Measurement, Slight Error May Exist ).Package List:1 xMusic Box MovementNote:To turn the bottom clockwork spring, the movement starts to operate, and the mushroom nail starts to rotate (you can make a unique music box).