If you’ve been eyeing this sleek and minimalist fitness tracker, act fast—this limited-time Prime Day deal won’t last long.

Get 15% off the Oura Ring 3 and Oura Ring 4 (newest model) during the final day of Prime Day today, in all shades and sizes.

In honor of Prime Day, Amazon is going against the norm with the first-ever price cut on Oura Ring 4: With a 15% reduction on all sizes, you can now buy the Oura Ring 4 in silver, size 10, for $297 from $349. Other sizes are also on sale, but some of them are already sold out.