I had purchased an aftermarket protective shield since both me and my friends are pretty inconsistent with our shots. The one that I purchased never fit right and could affect the reading of the GC2 sensors. I replaced it with this one that is excellent quality and fit. It fits very nicely around the GC2, has room for my HMT connector and is really a nicely built product. It has been hit by an errant shot, by the way, so I do recommend to anyone who has friends that can be sloppy with their shots.