This digital clock is perfect for chess and other games that require countdown, count up, bonus, and delay times. It's lightweight and small in size, so it fits in most bags conveniently and is portable to take to and from club or tournament events. Functions: Basic: Set basic time. BonusSet basic time and bonus time. DelaySet basic time, second reading times and time. Positive Timing: Set basic time to be 0 for overall rationing system Specifications: Material: ABS Color: Black / Yellow (Optional) Battery: 2 * AAA battery (included) Screen size: 103 * 23mm / 4.06 * 0.91in Item size: 140 * 88 * 45mm / 5.51 * 3.46 * 1.77in Item weight: 105g / 3.70ounce Package size: 150 * 100 * 50mm / 5.91 * 3.94 * 1.97in Package weight: 157g / 5.54ounce Packing List: 1 * Chess Clock