Check the listing for details. Lightweight Silicone Cover for Oura Ring 5 - Designed for S and M Sizes. Color: Black S, Condition: New. Listed at 7.84 USD. The real color of the item may be slightly different from the pictures shown on website caused by many factors such as brightness of your monitor and light brightness. Variety of for Sizes: Available in sizes S (6, 7, 8, 9) and for M (10, 11, 12, 13), this silicone case ensures a for perfect fit for a wide range of users, accommodating different finger sizes with ease.