Born for Apple Watch: Designed for Apple Watch Series 2/3/4/5/6/7/8/SE/SE2/Ultra, suitable for iWatch 38/40/41/42/44/45/49mm version. Note: ONLY for Apple Watches, not for any other brand's watches. Compact Watch Travel Charger: Features compact size of 71x42x15.8mm and light weight of 43g. The key-chain design allows you to hook it on your bag, preventing accidental loss. Small but Powerful: The integrated efficient polymer cells offer fast charging speed, fully charging a smart watch only takes 2~3h. Note:The type-C port is ONLY for input, not for output. Comprehensive Charging Protection: Thanks to the built-in over-current, over-voltage, short-circuit, and over-temperature protection, the charging safety can be better guaranteed, ensuring steady and faster charging during daily use. Fancy Light Ring: The blue light ring around the charging area displays how much of the battery is left(0-25%-50%-75%-100%). Note: Please charge your watch when the light ring is on.