To turn on / off, press the button underneath (Turn Off when the game is finished).

Generally, clocks should be pre-programmed with the applicable time control.

If so, simply press the top bar, to start, as you would a normal clock. (N.B. A white king / black king will be shown in the display. Before the clock is started, pressing the white bar will switch these symbols over).

Press the PLAY button - (in the centre), after the clock has been properly set
Press the PLAY button - To either stop/Pause or to restart again.

DISPLAY
The clock display will read as (hh:mm) unless the remaining time is 20 minutes, when (mm.ss) is shown.
The two clock faces will act independently to show "HRS/MIN" or "MIN/SEC".

SETTINGS
For time controls employing a Quick-Play finish, the additional time for the QPF is added automatically.
However, this is done when one player has used all of the initial time period.
At that point, the additional time is added to both clocks. (N.B. this is not when the prescribed number of moves have been made, only when the primary time period has expired on one clock).

A static BLACK FLAG is displayed on the clock which first reaches the end of the first time period and is displayed for the next five minutes. This is equivalent to the flag fall on an analogue clock. It does not of itself indicate a loss on time, merely that the time has expired. The clock will instantly add the QPF additional time and carry on running. Therefore, at this point, the players should check that the requisite number of moves have been made, just as you would when using an analogue clock. If the player whose clock is showing the BLACK FLAG has NOT made the required number of moves when this happens, the opponent may claim the game for a LOSS ON TIME.

When the final time has expired for either side, a FLASHING BLACK FLAG is shown on that clock, which does indicate a loss on time.

The clock counts the move numbers, incrementing the counter after each move by Black, however, the program does NOT include the number of moves required for a given time control.

You can check the move number at any time by pressing the +/# key (second from the left below the main display). Be aware, however, that the counter is not infallible because a player may have forgotten to operate the clock, so the counter may be out of step. Best advice is to rely on the scoresheets at all times.

Refer: FIDE Laws of Chess Article 6 - The Chess Clock.

To illustrate the above points, here is an example of the process of adding QPF time:

1 - In the illustration above, both clocks are displaying minutes and seconds (both clocks show the "min/sec" symbol). Note the symbol between the minutes and the seconds is a full stop - compare with hours and minutes which are separated by a colon.

In this example, the left clock face (Black) is showing 3 minutes and 10 seconds remaining (3.10), while White has 2 minutes and 3 seconds.

2 - If after 2 minutes and 3 seconds White has not moved then White's clock has reached the end of its primary time allotment and quick play finish time has been added (i.e. 30 minutes) to BOTH clocks. A black flag on the right will display to signify that this clock was the first to expire the first time period allowance. At this point the players will check their scoresheets to see that the required number of moves have been made; if not, in this example, Black can claim a win on time.

The clocks will look different from the above view in that with the addition of the extra 30 minutes, the clocks have switched back to displaying hours and minutes (the legend on each clock will show "hrs/min"). White's clock will therefore show 29 minutes (seconds no longer displayed, so the actual time might be 29 minutes and between 0 and 59 seconds). Black's clock will show 30 minutes plus the three minutes carried forward = 33 minutes.

3 - Finally, the clock does have a move counter, which is incremented after each move by Black (i.e. it doesn't count "half" moves). The move counter can be viewed at any time by pressing and holding the +/# button. If it shows 22 moves have been made by both players after White's move then White will have made his/her 23rd move but the counter will not increment to 23 until Black has also made 23 moves.

However, the clock's program does not record the number of moves required for the time control. This point is made to underline the fact that the BLACK FLAG only indicates the expiry of time.