In this locking lever position (picture left) the edge clamp is open. Pull the sliding jaw (picture right) forward with the finger grips until it presses against the workpiece.

Now the sliding jaw is in pressure postion at the edge of the workpiece. The locking lever is still in the "open" position.

Now lock the clamp by pushing the locking lever to the 1st locking position. You achieve light pressure.

If more pressure is required push the locking lever to the 2nd position.

If maximum pressure is required push the locking lever to the 3rd position as shown in picture left.