ULTRAHUMAN RING AIR

This one promises serious insights for fitness freaks

- Words Leon Poultney

If you want a smart ring that you can pretty much forget you're wearing, the Ring Air certainly lives up to its name. It's lighter than the others tested here and none of its sensors protrude from the inner surface, so it's perfectly smooth and comfortable to wear for hours, or even days, on end.

I opted for the raw titanium option in order to keep the bling factor down, but it perhaps goes too far the other way: it doesn't have those metallic tones when dropped on a hard surface, like proper gold or silver jewellery does, and when on the finger the rather plain flat surface looks like an offcut from some plumber's piping.

Sensors working overtime

When it comes to the hardware, the Ultrahuman Ring Air packs an infrared photoplethysmography (PPG) sensor, which takes care of blood oxygen saturation and heart rate, as well as six-axis motion sensors and a medical-grade skin temperature sensor.