Tolong jelaskan mengenai Arloji kedap air dari Jam tangan

Jam tangan kedap air memiliki satuan meter, atmospheres (atm), feet (ft), atau bar. 1 ATM = 10 meters, 1 meter = 3.28 feet. Berikut adalah penjelasan lebih rinci:

UK patent GB218487, Improvements relating to wrist watches, 1923 patent resulting from John Harwood's invention of a practical self-winding watch mechanism.