Amazon.com: Oura Ring Gen3 Heritage - Silver - Size 10 - Smart Ring - Size First with Oura Ring Gen3 Sizing Kit - Sleep Tracking Wearable - Heart Rate ,OURA ring Gen3 us10 Heritage Silver used,Oura Ring Gen3 Heritage Silver Size US9 Smart Ring Only tested | eBay,Oura Ring Gen 3-Horizon-size 10- Color silver. Smart Ring Condition is Open Box,Oura Ring Gen 3-Horizon-size 10- Color silver. Smart Ring Condition is Open Box,