This focus gauge is designed to be used in conjunction with the standard 2" focal length lens that ships with the Epilog Mini/Helix laser cutters. It should function as a replacement for the factory gauge. You'll need to press two 2-56 hex nuts into the top part so that it will stick to the magnets on the laser cutter.
Unlike the factory focus gauge, this one is not adjustable, so you may need to modify the model slightly to get perfect focus.
The author marked this model as their own original creation.