Feature：Positive timing，maximum 10 hours;Presettable countdown，maximum 10 hours;Alarm when the match is oven;Power supply: 1 pc AA battery(1.5v)，NOT INCLUDESize:135*90*35mmOperating insructions:ON/OFFInsert the battery，dial the [ON/OFF] to position “ON” switch ON，dial the [ON/OFF] to position “OFF” switch OFF.POSITIVE TIMINGIn the positive timing screen，press [Start/Pause/Setting] for 3 seconds to enter the coutdown seeting state，the “hour”digit starts to flash，press the[+] button，the flashing dight incremented by 1，press the [-] button，the flashing dight decremented by 1，press [Start/Pause/Setting] to switch to the “minute” dight flash，and so on to set other parameters.After setting，press [Start/Pause/Setting] button for 3 seconds to exit the setting and return to the countdown screen.Press [Left/Right] to begin the match，the tilt of the side is timing，when one side time runs out，then lost，the two sides stop timing，and alarm for 2 seconds.PAUSEIn timing，press the [Start/Pause/Setting] to pasue the timing，press again to continue timing.RESTARTIn the pause or end of the match，press [Start/Pause/Setting] for 3 seconds，the time of the two sides to the previous parameters，you can restart the match.NOTEWhen the display is dim，and press [Left/Right] button does not work.means that the battery should be replace at once.MAINTENANCEKeep away from hot sun or temperature to aviod display black;Keep away from corrosive liquid，sharp hard object impact;Keep away from high static objects，such as screen and so on.Package include:1x Electronic chess clock