The smart ring that suggests caffeine consumption window is getting $50 knocked off for Prime Day

If you’ve been eyeing up the Ultrahuman Ring AIR, now’s the time to act. As part of Amazon Prime Day 2025, the cutting-edge smart ring is down from $349 to $299, a tidy $50 discount on one of the lightest and smartest smart rings around.

There are similar deals available on the Oura Ring 4, which is selling for the exact same price on Prime Day. If you have a Galaxy smartphone, the Samsung Galaxy Ring is also on offer with over $100 slashed off its MSRP.

Ultrahuman Ring AIR: was $349 now $296 at Amazon

Ultrahuman Ring AIR is a feather‑light (2.4 g), titanium smart ring that tracks sleep, HRV, heart rate, skin temperature, SpO₂, activity, and recovery with no subscription required. Sleek, waterproof (100 m), and comfy, it delivers deep health insights and actionable nudges via the Ultrahuman app, all without the bulk of a smartwatch.

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Designed for people who want in-depth health insights without a bulky smartwatch, the Ring AIR tracks key metrics, including HRV, heart rate, SpO₂, skin temperature, sleep stages, and movement patterns, then feeds this data into the Ultrahuman app to help you fine-tune your lifestyle.

In our review, we said, "Thanks to the unique metrics and suggestions, the Ultrahuman Ring Air is the best smart ring for sleep tracking. Not only does it monitor your circadian rhythm, but it also suggests a daily window in which you should consume all your stimulants (e.g. tea, coffee) so as not to disturb your sleep."

Battery life is also solid, with the Ultrahuman Ring AIR lasting up to 6 days on a single charge. It syncs seamlessly with the Ultrahuman app, even after being in aeroplane mode, perfect for travel or low-battery phone days.

Extra perks, such as Cognitive Score, Movement Index, and detailed metabolic nudges, make it feel more like a personal coach than just a tracker.

Add in a sleek titanium build, 100m water resistance, and no subscription required, and you’re looking at a wearable that rivals Oura and RingConn, but with a sharper focus on metabolic and recovery optimisation.