We celebrate Casio Watch’s 50th anniversary by bringing back the very first ring watch. A whole new style of digital watch — both practical and playful — thanks to a miniature module and advanced metalworking technology.

Creating a ring-sized, full-metal version of the Casio watch’s complex form is no easy feat. To make this possible, we needed to use a special method of metal processing to inject a mixture of fine metal powders and resin into a mold. Using metal injection molding (MIM), the case, case back, and ring are molded in one piece, with even the dimpled design on the band faithfully reproduced. A special glass adhesive technique ensures a tight seal for a watch built to be water-resistant while still allowing the battery to be replaced. 

With an inner diameter of 20 mm and a circumference of 62.8 mm, the ring fits a size 22 finger (US 10.5, EU U) and includes two size-adjusting spacers, in size 19 (19-mm inner diameter) and 16 (18-mm inner diameter).

We downsized the standard watch module by a factor of 10 and combined it with a small button battery to create a 3-button digital watch that fits on your finger. Even at this small size, the watch features a 7-segment LCD that displays not only the time down to the second, but also the date, dual time, and stopwatch functionality.

Preset the time of your choice, and the ring watch gives off a subtle, flashing light — not only handy for keeping time, but also a poetic nod to the fleeting twinkle of time.

• Case size (L× W× H): 25.2 × 19.5 × 6.2 mm
  
• Weight: 16 g
  
• Case and bezel material; Stainless steel
  
• Water resistance: Water Resistant
  
• Power supply and battery life: Approx. battery life: 2 years on SR621SW
  
• Glass: Mineral Glass
  
• Compatible band size: 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.
• World time: Dual time
  
• Stopwatch: 1/100-second stopwatch, Measuring capacity: 00'00''00~59'59''99
  
• Alarm/hourly time signal: 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.
  
• Light: LED backlight, May not be visible in bright light.
  
• Light color: LED:White
  
• Calendar: Auto-calendar (28 days for February)
  
• Accuracy: ±30 seconds per month
  
• 12/24-hour format
  
• Regular timekeeping:
  Digital: Hour, minute, second, pm, month, date, day