The LEO has a timer and the following is written in the operating instructions:
By pressing the timer button (9) you can selectively set the operating time from 1-7h (e.g. 3h = LED 1h + 2h active / 7h = LED 1h, 2h, 4h active) . The selected time period is displayed below the timer key (9) with blue LEDs. Press once to set 1 h operating time, press again to set 2 h operating time, and so on. The remaining operating time is indicated by the lit LEDs below the timer button (9). The unit switches off automatically when the set operating time has elapsed. If no LEDs light up below the timer button (9), the unit is set to continuous operation.