Casio CRW-H001 Smart Ring Watch
Casio's original Ring Watch was a 50th-anniversary novelty nobody expected to matter, and it's since sold out repeatedly and now trades for triple its retail price on the secondary market. The CRW-H001 gives that hype item an actual job: a ceramic lining inside the ring houses a real health-tracking module, reading heart rate, blood oxygen, body temperature, and sleep straight off the skin, on top of daily steps, calories, and dedicated modes for walking, running, and cycling. And where most rings on the market are blank metal bands, this one keeps Casio's classic LCD front and center, showing the time, stopwatch, dual time, and calendar without ever opening an app, while a low-power vibration motor buzzes for calls, messages, and alarms. Currently sold only in China.

