You 't need a battery. Mechanical time manager, no battery, slight when walking, ringtones at of time It is easy to see. It provides a visual effect of the rest of the time. easy to use. Just turn the knob clockwise to the time you need you can better remind the children that time is up. Better time management Three placement positions - 1. Two folding legs can be opened and placed on a flat surface such as a table and counter. Can also hang Display type: pointer Movement: quartz Power type: battery Shell material: ABS Product size: about 190*190*40MM Color: black Package Contents: 1 * 60 timer Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.