Lowest price I've seen in a while for the RingConn Gen 2 (note, this is not the cheaper Air version). RRP is $499. Harvey Norman has them for around $450.
Edit: These do not require a subscription. This is the main draw to this ring for me.
It is worth getting a sizing kit ($2 at Amazon) to try on a few different fingers prior to getting it. It is meant to be most accurate on the index finger, followed by middle, then the ring finger. It is still OK on the ring finger though, maybe a few percent off. I found it most comfortable on the ring finger, so I'm getting that.
These rings are not really good/aimed at tracking workouts. Sleep tracking, steps, some daily heart rate monitoring is what I am planning on using it for.
Advantages over the Air version:
* Charging case with inbuilt battery, which charges the ring 10+ times
* Made from titanium instead of stainless steel (~0.5g lighter)
* Air has 10 day battery vs 10-12 for the standard Gen 2
* Sleep apnea tracking
You can get $5 off if paying by Visa, or $10 off if paying via the app (targeted). YMMV
Hm, $2 sizing kit recommended