How does that lens attach to the board?

I think mine is older and it has 4 screws into the board. Cost me $20 at a machine shop to bore out a Speed/Crown board. I also needed a skateboard thick piece of wood/metal between the lens and the board to clear the light trap. Thought that was a good idea anyway since the lens might like it. Screwed the lens to the wood, bolted the wood to the board....Nice little project that made me happy, happy, happy...