Usage: 1.Timing button operation method:pressed the left button, the left clock stop timing, the right clock start timing. Conversely, press the right button, the right to stop the timing, the left start the timing, both sides of the button at the same time pressed under half (that is, both sides of the button in the same horizontal position), two clocks are in the state of stop timing. 2.Second hand zero adjustment: By alternately operating the buttons on both sides, the two clock and second hands can be adjusted to the position of 12 o 'clock (zero) in turn, and the hour hand can be moved to the position of 12 o 'clock according to the direction of needle arrow on the back of the clock. In the game clock, the minute hand zero judgment takes the minute hand to push the judgment mark "little red flag" to the right to reach the position of 12, and the scale pointed by the minute hand at the moment when "little red flag" falls freely is zero. Specifications: Type: Chess Clock Material: Plastic Color: As Picture Size(L*W): About 18x7.5x11.5cm/7.09x2.95x4.53inch Battery: 1x AA Battery(not included) Package Included: 1pc x Chess Clock Note: 1. Due to the light and screen difference, the item's color may be slightly different from the pictures. 2. Please allow 0.5-2 cm differences due to manual measurement.