Smartphone screen protectors are notoriously bad. I've used a smartphone for over six years and in that time never used one that I liked. They're too difficult to put on, offer next to no additional protection, and are inferior to the glass the phone already has. So why would anyone in their right mind put a piece of weak, floppy plastic over it?\r\n\r\nI don't typically say yes to reviewing product genres that are typically worthless like smartphone screen protectors. Sure, our readers want to know about bad products so not to buy them, but daily use of garbage is a hassle and in our other coverage I make it very clear what technologies and accessories don't make the cut. Why I said yes to the Tech 21 Impact Shield I don't know, but it was a great decision.\r\n\r\nThe Impact Shield is as close as you can get to a hard glass protector for the iPhone's screen without making it another layer of glass. The hard plastic is made to be placed on the phone once -- correctly -- and never touched again. It adds a hard second level of protection to your smartphone screen without changing the texture, lessening the visibility of the display, or leaving those annoying air bubbles like you are all too familiar with.\r\n\r\n\r\n\r\nI say "correctly" very seriously. For most other screen protectors, you can take them off and put them back on properly anytime, no problem. The Impact Shield doesn't do that. Take a look at the picture above. The difference between a perfectly placed Impact Shield and a badly placed one is stark. Fortunately Tech 21 sent two Impact Shields; the first went on my iPhone, the second on another test device.\r\n\r\nOn my own, I put the Impact Shield too far to the right. The directions state where to place it, how to get rid of air pockets, etc., but it doesn't state exactly how to put it on the iPhone. I was off by no more than a centimeter, which made the right edges catch on various cases I test. When I tried to take it off, I accidentally broke into the layered plastic, and on the bottom right corner it started to peel. As you can see, the cover still works, but it's a mess. After I took it off the first time, it was impossible to remove air bubbles like I did originally.\r\n\r\nAll of this means only one thing: the Impact Shield is a great screen protector for the iPhone 5...if you put it on right. It's made to stay put and never be moved. It works excellently on both devices, but only looks good on the second iPhone, as you can see above. I've scratched it, treated it poorly, and even keyed one of the phones. No problem for the Impact Shield. I'm impressed with the protection it offers, but more importantly that it feels\u00a0just\u00a0like the iPhone's glass. The best protection is the kind that you never notice; the Impact shield is precisely that.\r\n\r\nBottom Line:\u00a0It's the only screen protector you should ever buy. And you might want to buy two in case you screw putting the first one on.\r\n\r\nThe Tech 21 Impact Shield is available for the iPhone 5, Samsung Galaxy S III, Galaxy S IV, Galaxy Note 2, Galaxy S III Mini, and iPad mini. Tested model MSRP is $30 from Amazon.