I was trying to find a way to buy more of them but they don't sell them online.
However, their one year warranty includes the screen protector.
I just called otterbox and they are sending me a new screen protector for free, and it doesn't use/void your warranty.
I found invisishields a pain to apply, and have a rubbery feel that I hate.
The body shield was easy to apply (static cling) but also has a rubbery feel (not as much as invisishield).