Sper Scientific 810035 Water Resistant Stop Watch, Large Display Sper Scientific 810035 Large Display Water Resistant Stopwatch. Sonically welded case ensures excellent water resistance. Large 5/8" high display for good visibility. Counts up to 24 hours with resolution of 1/100. Counts up to 24 hours Lap function Alarm clock Calendar Sper Scientific 810035 Large Display Water Resistant Stopwatch. Sonically welded case ensures excellent water resistance. Large 5/8" high display for good visibility. Counts up to 24 hours with resolution of 1/100. Counts up to 24 hours Alarm clock Calendar