Water Resistant mark
(重定向自Water resistant watch)

Water Resistant is a common mark stamped on the back of wrist watches to indicate how well a watch is sealed against the ingress of water. It is usually accompanied by an indication of the static test pressure that a sample of newly manufactured watches were exposed to in a leakage test. The test pressure can be indicated either directly in units of pressure such as bar , atmospheres, or (more commonly) as an equivalent water depth in metres (in the United States sometimes also in feet).