First of all, you need to make a text in the software and start marking. When the marking gets the strongest lighting, it means that the marking head is in right position and the focus is correct. After you confirm the marking head is in right position and the focus is correct, you can switch on the focus finder (①) by pressing it. The pointers of two red lights (②) will be on and the two lights will show the focus position.
Move up or down the marking head by pressing up/down button till the two red lights cross into one point, which means the focus is done. Otherwise, you need to adjust them. You need to use a screw to loosen the connection holder of the red light pointer. After you loosen one of the red light pointer, you can move it and let the red light pointer meet the other one, let them cross together into one point. Then you can tighten the red light pointer which is loosen before.
After that, you can put your workpiece under the marking head. Make sure that the surface level of the workpiece is the same level with that of the crossed point. For example, before you put your workpiece onto the machine table, the crossed red light point is on the surface of the machine table. If you provide you workpiece with the height of 2cm, the marking head should also move up by 2cm accordingly in order to ensure that the level of the crossed red light point is in the same level with the top surface of your workpiece.