[Sturdy Material] - Material: high quality wooden box and silver-plating metal Yunsheng Movement, sound is high quality, clear and sweet, no out of tune; Size: 10.4cm*9.4cm*5cm. [No Batteries Required] - The sound power from spring, use the key to turn the spring 3-4 circles, then release and will be playing. Full playing time (twist to the end) will be 3-4 minutes. [No Hand Crank] - This is a windup music box, not like hand crank music box, you need to shake the handle all the time. If you are tired with hand crank music box, then this windup music box can surprise you and make you relaxed!