The archive · Product Ideas · Product decision · 2024–2025
Casio CRW-001: a fully working digital watch shrunk into a steel ring — instant sellout
A functional digital watch built into a ring: one-piece metal-injected steel case, six-segment LCD and a replaceable battery — deliberately no sensors.
Casio Computer Co.
What it had to solve
In 2023 Casio sold ring-shaped watches inspired by its iconic digital models, but they were ornaments that could not tell time. For the 50th anniversary of its watch business it wanted the same object to actually work — and to do it without copying the sensor-heavy smart-ring formula.
How it works
Casio has built its watch business on tough digital timepieces, yet for the 50th anniversary of that business it chose a format usually treated as a gag: a watch worn on the finger. Unlike its 2023 ring-shaped ornaments, which were styled like Casio icons but told no time, the CRW-001 is a complete, working digital watch shrunk into a stainless steel ring.
The hard part was manufacturing. Casio used metal injection moulding, starting from powdered metal, to create the case, case back and ring as a single piece in a permanent US size 10.5, with spacers included for smaller fingers. Inside sits a module about one-tenth the size of a normal watch, driving a six-segment LCD, three buttons, an LED light, a stopwatch and an alarm that flashes the display instead of beeping; the SR621SW battery lasts about two years and is replaceable through a glass-adhesive seal that keeps the watch water-resistant.
The ring launched in Japan in December 2024 at ¥19,800 (about $128) and sold out almost instantly, followed by China and a $120 US release as the CRW001-1 in the same month. Tech and enthusiast outlets called its reception weirdly positive, and Casio restocked on June 20, 2025, strictly one unit per person, turning what could have been a novelty into a cult collector piece.
Why it lands
- It commits fully to the format — the ring really tells time — instead of selling another non-functional collectible.
- One-piece metal injection moulding turns a structural puzzle, a sealed ring-shaped watch case, into a single elegant manufactured part.
- Keeping the ring deliberately dumb — no fitness tracking or notifications — makes it a coherent anti-smart-ring statement.
- A replaceable battery and water-resistant glass seal keep a tiny wearable serviceable for years, which is rare in the category.
What it did
Launched in Japan in December 2024 at ¥19,800 (about $128), the ring watch sold out almost instantly, followed by a quick sellout in China and a $120 US release (CRW001-1) the same month. Enthusiast and tech coverage described its reception as weirdly positive, and Casio restocked on June 20, 2025, first-come first-served with a one-per-person limit.
What you can take
Give the joke real engineering and it stops being a joke: Casio solved one-piece moulding, water resistance and battery service for a ring-size watch, so collectors paid for craft, not gimmick.
Since then
After the December 2024 sellouts, the CRW-001 developed a cult following: Casio's official store and selected third-party retailers restocked on June 20, 2025, strictly one unit per person, and interest kept resurfacing online. Coverage highlighted the repairability — the SR621SW battery can be swapped, more easily than in most smart rings and watches — and hands-on videos showed the small display staying legible while worn. For a 50th-anniversary novelty, the ring became Casio's clearest recent proof that it can treat an unserious format as serious engineering.
Sources
- Casio's first smart ring has innovative features like a stopwatch and flashing alarm
- Casio's odd watch-shaped smart ring is actually coming to the US
- Casio's high-in-demand CRW-001-1JR ring watch is finally getting a restock after months of waiting
- Casio CRW-001 ring watch unboxing and hands-on video by WatchDavid
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