The Monster Bash shooter lane plastic is often broken. This replacement is cut from blue tinted fluorescent acrylic. It has polished edges that appear to glow slightly.
The material is acrylic and, although it has a hard surface that polishes nicely, it will break if you bend it too far during installation. Once installed, it will stand up to normal use. Don't overtighten the screws or it will craze.
Installation requires removing (or loosening if you are tricky) the right wireform to get to the screws at the top of the shooter lane. The spacers will struggle a bit with the thicker material, it will go better if you cut off th little barbs. Insert the spacers into the plastic, then screw the screws through so that everything is pre-assembled. Screw the screws just enbough into every hole so that they bute, and then screw each one about half way in. Them go back and screw all the screws all the way in. Don't overtighten. You'll find that the new plastic is much more substantial than the original.