Differences in quality ...

Battery works, fits very well and is very convenient.
However, the quality varies, have so far bought three batteries and only the first ordered looked new. The other two orders I briefly considered it to be claimed as scratches and dirt on the battery pack is available. after a few weeks use but seems the most important, so the inner workings to be fine. So far one of the best batteries that I've installed for the iphone 3, even if they look visually somewhat questionable.