•CHARGERS ARE SIZE-SPECIFIC - Your Oura Ring 4 size can be found on the inside of your smart ring. •FSA/ HSA ELIGIBLE - We can accept FSA or HSA funds for the following: Oura Ring, additional chargers, and shipping. •CHARGING TIME - Your Oura Ring 4 typically charges fully in 20-80 minutes depending on its current battery level. •BATTERY LEVEL IN OURA APP - You can check the battery level by tapping the circular icon in the upper right-hand corner of the Home home tab. •CHARGE LEVEL BEFORE BED - It’s important that your Oura Ring 4 sleep ring be charged to at least 30% before going to bed. •CONNECT THE USB CABLE - Connect the USB charging cord to your charging dock and plug the other end into a power source, such as a USB wall plug, laptop, or power brick. •CHARGING DOCK - The LED will pulse white while your smart ring is charging. •LEARN ABOUT NOTIFICATIONS - When the LED turns green, your ring is fully charged. You’ll receive a push notification from your Oura App when charging is complete. This also applies for low battery notifications. •POWER CORD COMPLIANCE - The USB-C to USB-C Oura Ring 4 Cable Cord is intended to be supplied by an external 5Vdc supply that complies with IEC 62368-1 standard. The Oura Ring 4 Charger is the only way to charge your Oura Ring 4, the revolutionary smart ring. This USB-C cable charger is size specific, so be sure to get the size that fits your Oura Ring 4. You can find your Oura Ring 4 size on the inside of your Ou