Can I add that I have bought many things from this firm, including iPhone cases and external power supplies. Generally, but not always, I have found their products ok. I am currently using an iPhone Power case that has worked flawlessly for the past 9 months. I also have one of their external battery power units rated by them at 1900mAH that I regularly use when not using the case, and that gives me almost 2 complete charges, so I believe the rating in this instance to be correct. About 18 months ago I also used their batteries to replace ones not holding a charge in both an iPod Video, and Nano 2nd gen, and they are both still going strong. So you are right to beware, but not all cheap things are useless or a con, there are some bargains out there, and this MIGHT be one of them.
Has anybody actually tried it yet ?