NO BATTERY NEEDED: Wind-up mechanism ensures that you'll never have to interrupt a game to replace a battery Professional mechanical analog Chess Clock. INCREDIBLY ACCURATE: The timing is accurate, and the daily error is no more than 1 second. SO SIMPLE TO USE: Just wind it up and set the hands before . The tilted base makes it easier to view the clock dials during Recommend: Available for Chess,Chinese Chess, and I-GO. colour: as shown Material: Plastic Size: 15x5.5x9cm Package Contents: 3 x Chess Timer Only the above package content, other products are not included. Note: Light reflection 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.