Usage Tips: Timing rules include BASIC, BONUS, DELAY, BYO-YOMI, and COUNT-UP. It automatically switches to positive timing mode after countdown. User-defined time can be set up to 9:59:59. Different timing parameters can be set for both sides, and the time can be modified during the game. It can automatically save the parameters set before shutdown. Step recording function: You can view or modify the number of steps taken up to 999 steps. Sound and shutdown function: You can turn on/off the voice prompt or turn on/off the chess clock. Functions: BASIC: Timing mode in current time DELAY: Delay mode in current time BONUS: Second increasing mode in current time BYO-YOMI: Go countdown mode in current time Battery: 2 x AA battery (not included) Color: Black Material: ABS Package Contents: 1 x Chronograph 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 to be slightly different from the real thing. Measurement allowed error is +/- 1-3 cm.