NewJourney silicone ring covers are compatible with Oura Ring Gen 4/ Gen 3 Horizon/ Gen 3 Heritage, UltraHuman Ring AIR. Oura ring 4 cover features elastic silicone, fits ring sizes: S for 6/7/8/9/10, M for 11/12/13/14/15. Made of soft silicone, this oura ring gen 4 cover will not rub your skin and is easy to slip on and off your ring. The 0.8mm thickness design ensures comfortable wearing, which can well protect your ring from scratching and keep your fingers nimble. What you get: 8 oura ring covers compatible with Oura Ring Gen 4/3. (Note: Ring not included) Compatible with Oura Ring Gen 4/ Gen 3 Horizon/ Gen 3 Heritage Cover - Charging Directly with Protector, Elastic Silm Silicone Case for Working Out