Can I replace my iPhone 4S screen with a glass digitizer?

I bought a pink iPhone 4S glass digitizer and I want to replace my cracked screen, is that the right screen to replace it with? This is the one I got:

http://item.mobileweb.ebay.com/viewitem?index=0&sbk=1&nav=SEARCH&itemId=290848677797

You can't replace it, but cover it.