A total of 59 timing rules in 6 categories. Each timing rule can set the basic time and auxiliary parameters. Different basic time and auxiliary parameters can be set for the left and right sides respectively. During the race, the basic time and auxiliary parameters of both sides can be changed. When you turn off the machine and turn it on again, you can keep the rule parameters before turning off the machine. DC3V power supply Power Suplly: two No.5 batteries(Not included batteries) Colour: Blue Material: ABS Size: 182x100x63mm Package Contents: 2 x Chess Clock 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.