Take this as something of a PSA for those of you who obsess over keeping your phone scratch-free: avoid the $50 InvisibleShield glass screen protector for the Galaxy S8 and S8 Plus. Paying $50 for a piece of glass that sticks to your phone is objectively stupid. The thing is overpriced by a mile. But more importantly, it’s just not very good. Best Buy sells it. So do some of the carriers. It will likely be one of their recommended add-on purchases when you walk in to buy the phone. Don’t get ripped off.

First, some background: curved smartphone screens have proven to be a real pain for Zagg and the dozens of companies on Amazon (that sell way cheaper tempered glass protectors) for some time now. Even when the displays themselves aren’t curved, phone makers often curve the glass slightly at the sides for a more ergonomic feel. The Google Pixel is one example of this. Even the iPhone 7 does it. In these instances, you’ll find a lot of screen protectors try to cover the display area only and stop short of providing edge-to-edge coverage.

Because when they try to do that, they usually fail and leave an ugly “halo” around the entire phone’s border where the screen protector’s adhesive isn’t fully sticking to the device. Companies have tried a few ideas to resolve this; some screen protectors have color-matched bezels with adhesive only on the perimeter of the glass and not on the display area. It creates the appearance of edge-to-edge protection, but it also creates an air gap between your phone’s screen and the screen protector. That reduces touch sensitivity and can detract from the screen’s quality. Bad approach.

Unfortunately, Zagg / InvisibleShield took this kind of approach with the $50 Galaxy S8 screen protector. The entire thing is clear, but it only sticks to the phone at the sides, leaving that unwanted air gap. Feedback on user forums has been consistently bad, and the product’s rating has already bombed to hell on Best Buy’s website. So you should avoid it and save $50.

You’re probably better off with the more traditional (and significantly cheaper) film-based InvisibleShield for the S8, or a different plastic screen protector from Amazon that adheres to the entire surface of the phone. Verizon has its own glass screen protector; it also only sticks to the S8 at the edges, but hey, it’s slightly cheaper.

Making a curved glass screen protector at an appealing price is probably a challenge that would put a lot of these Amazon-based accessory companies out of business, so it might be awhile until there’s an ideal solution. Perhaps Samsung could just make one itself? Easy $30 in the pocket. If I were Zagg, I’d probably just pull this thing from the market. I get the appeal of getting that day-one attach sale, but this really seems like a miss.

Maybe just don’t use a screen protector at all.