Prepare for picnics, yard functions, date nights and anything in betweenGarden accessoriesPicnicware 100M Water resistant: Using a h2o resistance of as much as 100M you can easily cope with most scenarios in everyday life, such as washing palms, rain, swimming(be sure to tighten the crown when going into the water). https://www.watchesworld.com/a-history-of-watch-reference-numbers/