Made of durable ABS plastic casing, safe, eco-friendly and durable Suitable for Chinese chess, international chess games and board games The product is divided into left and right movements, and each full spring can last for no less than 36 hours. The daily error of travel time accuracy is ±3 minutes Instructions: 1) Put the chess clock on a flat table before use. 2) Press the direction indicated by the arrow on the back cover to wind up the mainspring fully. After the mainspring is tightened, do not twist it hard to avoid damage. 3) Set the needle: first set the minute hand to the 12th position, or set the minute hand to any indicated position as needed. When setting the hand, be sure to turn the clock in a vertical position to avoid the minute hand being 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 to start, press the right button, the right clock stops and the left clock starts to start (but it is not advisable to hit the button hard to avoid damage). 5) Speed adjustment: If there is a speed error, use a small metal rod to adjust the speed mechanism in the hole in the direction pointed to the left and right of the moon-shaped hole in the back cover. Specifications: Material: plastic case, zinc alloy movement Product size: 15x5.5x9cm