Casio CRW-001-1DR Digital Stainless Steel Ring Watch

The ring has an inner diameter of 20 mm and a circumference of 62.8 mm, fitting a size 22 finger (US 10.5, EU U). Two size-adjusting spacers in size 19 (19-mm inner diameter) and 16 (18-mm inner diameter) are included.
Water resistant
Dual time
1/100-second stopwatch
Auto-calendar
12/24-hour format
Time flash (daily and every hour on the hour).
The Time Flash light may not be visible when ambient lighting is bright.
Time Flash is intended for entertainment purposes.
LED backlight (May not be visible in bright light.)