1. No battery required, clockwork, easy to use, similar to quartz movement 2. Divided into left and right movements, each full spring can last for at least 36 hours, and the daily error in running accuracy is about 3 minutes 3. Material: plastic case, zinc alloy movement 4. Maintenance: The chess clock should be protected from contact with corrosive substances, avoid exposure to sunlight, rain, drops, and proximity to strong magnetic fields 5. Size: approx. 15x5.5x9cm 6. Weight: approx. 280 grams Instructions: 1. Place the chess clock on a flat table before use 2. Push in the direction indicated by the arrow on the back to fully wind the spring. Once the spring is wound, do not turn it hard to avoid damage. 3. Set the hand: first set the minute hand to the 12th position, or set the minute hand to any specified position as needed. When turning the hand, make sure to turn the clock in a vertical position to avoid the minute hand getting stuck on the indicator flag and causing the minute hand to shift. 4. Start: Press the left button, the left clock stops and the right clock starts, press the right button, the right clock stops and the left clock starts (but it is not advisable to press the button hard to avoid damage) 5. Speed adjustment: If there is a speed error, you should use a small metal rod to adjust the speed mechanism in the hole in the direction pointing left and right of the crescent-shaped hole in the back cover