?: Are you looking for a case or a full body screen protector for your iPhone 5 ?
The full body protector has the clear film you can put over the phone's screen as well as a "screen" protector you put on the back of the phone to protect your finish. I prefer a full body screen protector to just covering the display screen, I also put my Case right over it but usually only when I am travelling and more likely to drop my phone. Cases definitely give you more protection though for preventing shattering, thus "impact resistant" as you say. I get both from XtremeGuard.com and have used them over the past few years. The full body screen protector I use gives a lot of protection from scuffs and dings.
Good luck and Thanks for all the fish ><((.>