Timing rules include BASIC, BONUS, DELAY, BYO-YOMI, and COUNT-UP; the device automatically switches to positive timing mode after countdown. User-defined time can be set up to 9:59:59, with different timing parameters available for both sides, and time settings can be modified during operation. The device automatically saves previously set parameters before shutdown. Step recording function allows viewing or editing of moves taken, up to 999 steps. Sound and shutdown settings: users can enable or disable audio prompts, as well as turn the chess clock on or off. Functions: BASIC: Standard timing mode in current time DELAY: Delay timing mode in current time BONUS: Bonus time added per move in current time BYO-YOMI: Go-style countdown timing mode Power source: 2xAA batteries (not included) Note: No installation guide included; professional installation is recommended. Please verify the product details carefully to ensure this item meets your needs. Product design may vary slightly between batches; minor differences in appearance or color may occur, which do not affect functionality. Color: Dark Blue Material: Plastic Package Contents: 1 x Chess Timer Only the items listed above are included; other items are not part of the package. Note: Lighting conditions and display settings may cause slight variations in the color shown in images compared to the actual product. Measurement tolerance is +/- 1-3 cm.