Count Up setting:
1. Press key "START/ TOP (ST/SP)" to start count up;
2. Press any key to stop counting and press key "MN(M)" or "SEC(S)" to reset;
Countdown setting:
1. Press key "MN(N)" to set minute and "SEC(S)" to set second;
2. Press key "START/ TOP (ST/SP)" again to start countdown.
Battery Replacement:
1. When the timer display is unclear or sound is weak, it needs to replace the battery;
2. Powered by AAA battery (not included).