No technical label exists, either on device and battery. The ce mark on the label rises doubts about its autenticity the operation manual it's a big joke and again there's no reference about the model, and technical specs are missing. No way to know what buttons do, other than guessing or relying on own experience with similar products.
All in all, there are doubts about safety, and how to use it properly. Is it a good bargain, or will it be a waste of money?