Oura | | Refurbished Excellent | Ring 4 | Smart Ring | Size Before You Buy with OR4 Sizing Kit | Size 10 | | 2024) | Black | Best Buy

$249.99

Ultrahuman | | Refurbished Excellent | Ring AIR | Smart Ring | Size Before You Buy | Size 10 | | 2023) | Space Silver | Best Buy

$299.99

Renpho | | Smart Ring Health Tracker, Sleep Activity Monitor Long Battery No Subscription Titanium | | 2025) | Silver | Best Buy

$199.99

Oura | | Ring 4 | Smart Ring | Size Before You Buy with OR4 Sizing Kit | Size 10 | | 2024) | Gold | Best Buy

$399.00

Oura | | Refurbished Excellent | Ring 4 | Smart Ring | Size Before You Buy with OR4 Sizing Kit | Size 10 | | 2024) | Silver | Best Buy

$152.99