This is a sizing kit for the Ultrahuman Ring Air, allowing you to measure your finger size and check the color. I received this from someone who purchased it from the official website. Please use this to confirm your size, as the sizing is different from the Oura Ring. ▼Contents: Ultrahuman Outer Box Ultrahuman Ring Air Sizing Kit Box Ultrahuman Ring Sizing Rings (10 sizes) Ultrahuman Ring Sizing Kit Guide ※Ultrahuman Ring itself is not included. #Ultrahuman #Smart #Ring #Sizing #UltrahumanRing #SmartRing #SizingKit