Best way to describe this product, is to call it a layout grid ! Package includes 8 pieces approximately 4" x 5.5".
They are in a grid pattern and would be used for laying out markings or places to drill, etc... Check out the
cartoon below for an idea of how to use it.

From HIQ Website Translation:

And squares pattern carved in 1mm units, that you can put on the seal of the triangle pattern on the plastic, you will be able to make accurate drilling and cutting. Those that had decided the location of the drilled hole in the eye size until now, by the use of this seal, and left and right symmetry, accuracy depending on the idea, such as regular intervals will increase rapidly. Please also find such as the original use. So you can re-peeling, or cut out a number of plastic board to create a template, can be useful to the opening or drilling of the guide in the same pattern. 0.5mm from getting to the grid seal is also popular for those to your own model railroad you want a precise cut. Masumetaipu is cut out of 90 degrees.