Beginning March 7, the Oura Ring and complementary accessories will be available on Amazon through Oura's new storefront. The smart rings start at $299 and are available in a variety of sizes, styles, and metallic finishes.

Despite the popularity of Oura's fitness tracking rings, until now customers have been limited to purchasing them through Best Buy or directly from Oura's website. While these choices do not stop Oura's rings from leading the smart ring market, Amazon is the world's largest online retailer and the e-commerce destination of choice for millions of shoppers.

Buying Oura Rings through Amazon means that Amazon Prime members receive fast and free delivery on their Oura Ring orders. Nevertheless, Oura sells the same sizing kit that comes free with any purchase on the brand's website for $10 on Amazon.

Speaking from experience, skipping the sizing kit is not an option. I usually wear a size 7 ring, so when I first ordered the Oura Ring, I assumed I would need that size. However, after trying the sizing kit, I found that I needed a size 8 for the most comfortable fit.

However, if you don't want to order the $10 sizing kit from Amazon, you have two options. You can either ask someone you know if they still have it, or you can go to a Best Buy store and try it on in-store.

You can also purchase a fitness tracking ring while you are at Best Buy.

Otherwise, as someone who has lost a charging station before, I can now order a replacement from Amazon for $59 and it will be delivered quickly. If you travel between multiple homes or travel frequently, it might be wise to purchase a second charging base for convenience.

The Oura Ring is currently the most mainstream smart ring. Samsung's Galaxy Ring will be available later this year, but Oura is certainly ahead of the curve. The company's new retail partnership with Amazon has also helped its cause.

Compared to traditional fitness trackers and smartwatches worn on the wrist, devices like the Oura Ring are more discreet and designed to be worn for days at a time on a single charge. They can also be worn while sleeping for advanced sleep tracking and recovery data.

To give it a jewelry look, the Oura ring is available in two styles and six finishes. Final prices range from $299 to $549, depending on the style and finish.

But the price goes beyond the initial hardware purchase; Oura charges a monthly membership to access its full suite of health metrics, which costs $5.99 per month. If you are not confident in that commitment, it appears that Samsung may offer a similar service for free with the Galaxy Ring.