Casio's quirky new smart Ring Watch takes on Oura with heart rate and sleep tracking

Smart rings are all the rage these days, and Casio is the latest player to jump on the miniature fitness wearable trend. We have known for a while now that the Japanese watchmaker was readying a smart ring watch with advanced health tracking capabilities. Today, the company officially took the wraps off the CRW-H001M-8, a fitness-focused take on the CRW-001 Ring Watch, which arrived in late 2024.

Unlike a faceless tracker like the Oura Ring (curr. $299 on Amazon) or Whoop, the Casio CRW-H001M-8 is a fully functional mini-watch that doubles as a smart ring. Beneath that classic silver LCD face lies a surprisingly robust health-monitoring module that enables continuous heart rate tracking, blood oxygen level (SpO2) monitoring, sleep tracking, and even body temperature measurement. As you would expect from a modern wearable, it can also track your daily steps, estimate calories burned, and offer dedicated sports modes for walking, running, and cycling, alongside menstrual cycle management.

All of that health and fitness data can be viewed directly on your smartphone via the companion AIZO Ring app, which is compatible with Android, iPhone, and HarmonyOS devices.

The tiny ring watch even features a built-in vibration motor that quietly alerts users to incoming calls, messages, silent alarms, and charges via a pogo pin magnetic charger.

The CRW-H001M-8 comes in three sizes: small, medium, and large. Casio appears to have ditched the plastic size-adjusting spacers included with the standard CRW-001, likely because removable spacers would interfere with the optical sensors on the inner surface.

As far as dimensions are concerned, the Ring Watch remains almost unchanged from the 2024 version, measuring 25.3 × 19.5 × 6 mm , although it now weighs 19g instead of 16g. And don't forget it's still a Casio, so you get all the standard timekeeping features like a stopwatch, alarms, LED backlighting, and an automatic calendar.

Casio claims the rechargeable smart module delivers roughly four to six days of battery life, with up to 25 days on standby, while the watch battery itself is rated to last around two years.

Pricing & Availability

Casio's smart ring watch CRW-H001M-8 is launching first in China for 1,990 yuan (~$294), with a wider global rollout likely to follow soon. It's available in a single silver color and ships in a special presentation box.

Specifications

• Model: Casio CRW-H001 Smart Ring Watch
• Price: 1,990 yuan (China)
• Available colors: Silver
• Available sizes:
  • CRW-H001S-8 (Small / No. 9): 19.3mm inner diameter, 60.7mm circumference
  • CRW-H001M-8 (Medium / No. 10): 20.1mm inner diameter, 63.1mm circumference
  • CRW-H001L-8 (Large / No. 11): 20.9mm inner diameter, 65.6mm circumference

• Dimensions: 25.3 × 19.5 × 6mm
• Weight: 19g
• Case and bezel material: Precision steel
• Glass: Mineral glass
• Water resistance: Water resistant for everyday use
• Display: LCD with white LED backlight
• Connectivity: Bluetooth
• Companion app: AIZO Ring (Android 7.0+, iOS 13+, and HarmonyOS)
• Battery life: Up to 4–6 days per charge (smart module), up to 25 days standby
• Watch battery: Approximately 2 years
• Charging: USB charging
• Health features: Continuous heart rate monitoring, blood oxygen (SpO₂) monitoring, body temperature tracking, sleep analysis, health reports, menstrual cycle management
• Fitness features: Step counting, calorie tracking, walking, running, cycling, training logs, and training analysis
• Smart features: Vibration alerts for calls, messages, silent alarms, calendar reminders, custom reminders, and health anomaly notifications
• Watch functions: World Time, second time zone, 1/100-second stopwatch, automatic calendar, 12/24-hour time formats, hourly time flash, ±30 seconds/month accuracy