ULTRAHUMAN Ring AIR Sizing Kit - Size First Before You Buy - Choose from 10 Sizes - Sizes 5 to 14 - Find The Perfect Ring Size - Smart Ring Sizer SIZE FIRST - Ultrahuman Ring sizes are different from standard ring sizes. Purchase sizing kit first to get the perfect ring AIR size. Ring AIR is available in 10 sizes from 5-14. TRYING THE SIZING RING - It is important to first use the sizing kit to determine the ring AIR size. Wear your ring sizer for at least 24 hours to know your fit. Wear the ring such that the engraved size number is toward the palm of your hand. FINDING THE CORRECT FINGER - For optimal comfort and advanced sleep tracking, we recommend you wear the Ultrahuman Ring AIR on your index, middle, or ring finger. FIT CHECK: You will get highest data accuracy and optimal comfort with a properly fitting Ultrahuman Ring. Here are a few simple ways to assess this ? If you rotate the ring on your finger, it should not rotate freely. CHOOSE YOUR RING: After you've precisely determined your size using our sizing kit, head over to Amazon to order your Ultrahuman Smart Ring. BUILD QUALITY: While our sizing kit is made of high-grade plastic, the Ultrahuman Ring stands leagues apart in its material composition. Crafted from space grade titanium and coated with scratch-resistant tungsten Carbide, your Ultrahuman Smart Ring promises superior quality and durability. Sleep Index is derived to help you understand the various sleep stages such as Deep sleep, REM sleep, Light sleep and being Awake. During different stages of sleep, different metabolic processes of the body occur for growth, repair, restoration, and maintenance. Shipping We offer FREE shipping on all orders! We ship within Three business days of payment, usually sooner. We use a selection of shipping services such as UPS, FedEx, USPS etc. We only ship to the lower 48 states, no APO/FPO addresses or PO Boxes allowed. Local pickups and combined shipping options are not provided at this time. Return You can return a product for up to 30 days from the date you purchased it. Any product you return must be in the same condition you received it and in the original packaging. Please keep the receipt. Payment We accept payment by any of the following methods: PayPal Please pay as soon as possible after winning an sale, as that will allow us to post your item to you sooner! Feedback Customer satisfaction is very important to us. If you have any problem with your order, please contact us and we will do our best to make you satisfied. Contact Us If you have any queries, please contact us via. We usually respond within 24 hours on weekdays. Please visit our store to check out other items for sale! Thank you for shopping at our store.