A useful LiIon charger that you can probably use in any USB port. Therefore, it is perfectly all right, that is not supplied power adapter. It requires, moreover, a USB power supply with 500 mA, much more I would not take, because I'm not sure if the charger is not charging then with too much power.
The price is absolutely reasonable, the charger does not look cheap despite the size. The design is optimal for traveling.