Usage Tips:Timing rules includes BASIC, BOUNS, DELAY, BYO-YOMI and COUNT-UP, it automatically switches to the 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 step taken uo to 999 step. Sound and shutdown function: you can turn/off the voice prompt, or turn on/off the chess clock. Functions:BASIC: Means timing mode in current time DELAY: Means current delay mode in current time BONUS: Means second increasing mode in current time BYO-YOMI: Means Go countdown mode in current time Battery: 2 x AA battery (not included) Colour: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 a little different from the real thing. The measurement allowed error is +/- 1-3cm.