Waterproof Card Holder And Metal Casing

A waterproof card holder includes a card holder frame, a cover plate, a sleeve integrated with and extending from an inside of the cover plate, and a waterproof mechanism in the sleeve. A through-hole of the sleeve penetrates through the sleeve and cover plate. The waterproof mechanism includes a first end portion limited inside the sleeve, a second end portion having an outer diameter smaller than that of the first end portion, and a waterproof ring sleeved on a periphery of the first end portion and forming a sliding sealing structure with the sleeve. The sleeve includes first and second openings respectively disposed at two ends of a sleeve body. The first end portion is limited to be only movable within a stroke between the first and second openings. The second end portion being capable of passing through a first opening to be in contact with a card retracting mechanism.