Ive been using this for a few months now. Its a lot better than the cheap one I had before. If you have a k800i and you want to protect it from scratches and knocks and bashes that occur from regular use, then you have to buy this. Its really cheap and will protect the screen from becoming scratched. It seems durable (as my other one had broken at this point) and it is relatively easy to put on and take off.
The only thing preventing me from giving it a perfect five is the small crack thats appeared on the back where the slider and speaker are (probably because its the thinest part of the case and usually has the most pressure applied to it).

fits great to the phone and does a good job but mine broke within the first two weeks and has resulted in little bits of sellotape to hold it together

order mine on saturday got it on friday I was not in any rush to get it good for its price if it breaks i get the proper case I got it just to try.