Use method. 1) timing button operation method, press the left button, the left clock to stop timing, the right clock to start timing. Conversely, press the right button, the right side to stop timing, the left side to start timing, both sides of the button at the same time press the halfway (that is, the two sides of the button in the same horizontal position), both clocks are in the stop timing state. (2) second hand zero adjustment by alternately operating both sides of the button, the second hand of the two clocks can be adjusted in turn at the 12 o'clock position (zero), respectively, in accordance with the direction of the on the back of the clock dial needle hole dial the hour hand, minute hand to 12 o'clock position. Timing, the minute hand zero position to distinguish the minute hand to push the whole point of the judgment mark "small red flag" to the right up to 12 o'clock position, to ""small red flag"" free fall instant minute for the scale of the alignment of the zero position. Translated with .DeepL.com/Translator (free version) Colour:black Material:plastic Size: 18 x 6.5 x 11.5CM Package Contents: 1 x Chess clock Note: 1 AA battery is not included 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. [Accurate Timing]The timing is accurate, and error does not exceed 1 second.It is suitable for timing clocks of various chess games. [Light and Handy]Sturdy plastic shell, light and handy, easy to carry, easy to carry, suitable for novelty, entertainment and practicality. [Molding Process]The shell adopts a unique molding process, which allows the clock to be placed at a small angle for better viewing, anti-glare, and large-screen reading. [Game Clock] clock adopts a mechanical structure with a timing start button.It is simple to operate: press the left button, the left stops timing, the right starts timing, and vice . [Practical Clock]Practical PQ9905 quartz analog chess clock, suitable for Chinese chess and chess.