This is a simple plastic that pops into the hole where the LEDs backlighting the billboard are located. It even sticks to the backboard adhesive plastic so no screwing or hardware required. Simply remove the protective paper from both sides of the plastic and insert into the hole and gently adhere it to the backboard overlay. These also have the benefit of making the lighting look a lot more even. Photos don't really capture how much this simple mod improves the look of the billboard.

NOTE: THIS IS THE SAME PART FOUND IN THE JAWS PLASTIC PROTECTOR PRODUCT PAGE. Please order from that product page.
https://pinside.com/pinball/market/shops/1167-gameroom-mods/10279-stern-jaws-plastic-protectors