For the watch style choices, to the consumer a few suggestions, only for reference when buying watches. First, try to buy waterproof watch Watch is not waterproof or bad case seal, easy to make the watch heart failure, such as: water or moisture into the table heart, rusty steel parts, quartz watch circuit failure, serious may also damage parts, and even some Small dust, fiber can also drill into the watch heart, the watch stop walking or walking time is not allowed. On the contrary, good waterproof watch can ensure long-term accuracy of travel time and reduce unnecessary maintenance. Waterproof watch case back cover or The dial has a mark (WATER RESISTENT or 3ATM). In general, the back cover is tightened than the back cover for the press-in waterproof performance may be better, while the circular back cover than the square is easier to do