Mechanical structure: Using the mechanical structure with the timed start button makes the timed operation intuitive, convenient and accurate. Chess: no batteries required, clock operated, convenient to use, similar to the mode of operation of a quartz clock. It is a timing tool used in most chess games in Europe and America. High precision: the daily error does not exceed 1 second, applicable to the timing clock in various chess tournaments. Wood : Made of wood and plastic, it is strong and durable, not easy to break. Wooden color design, workmanship.Special maintenance]: chess bells should avoid contact with corrosive substances and avoid exposure to sunlight, rain, water droplets and near fields strong magnetics.Specifications:This chess clock does not need batteries, clock drive, convenient and simple to operate, similar to the working way of quartz clock.Material: plastic case , copper zinc alloy movementProduct size: 15x5.5x9cm Packing box: 19x7.5x12cm Chess bell net weight: 290 grams, + color box is 360 grams Suitable for Chess, Chinese Chess, Go, etc. Instructions for using the chess bell: 1). The running clock adopts start push button type mechanical structure with timing, running timing operation is intuitive, convenient, accurate when walking, daily error is not more than 1 second, applicable to various chess race timing clocks.2). Operation method:A) Chronograph button operation method, press the left button, the left clock stops the Chronograph, the right clock starts the Chronograph. Instead, press the button on the right, stop the Chronograph on the right, start the Chronograph on the left, press both buttons simultaneously on the bottom half (i.e. both buttons are in the same horizontal position), the two bells are in the stop state of the chronograph. B) zero adjustment of the second hand By alternately operating the two buttons on both sides, you can adjust the two second hands of the clock at the 12 o'clock position (zero position), respectively in the direction of the arrow of the dial hole on the back of the clock, the minute hand at the 12 o'clock position. Match clock, zero discrimination minute hand with the minute hand to push the whole "small red flag" point decision sign upward right to reach the 12 o'clock position, with "small red flag" free fall of the minute alignment scale is zero.4. Care and maintenanceThe chess clock should come into contact with corrosive objects, avoid exposure to sunlight, rain, dropping and close to strong magnetic fields Note: The data are all Manual measurements, please allow 1 - 3cm error, due to the difference in light and display, there will be some color difference, depending on the physical object received.