Less than a month in my possession. Only worn a handful of days. THE REVOLUTIONARY SMART RING - Track your sleep, activity, stress, heart rate and more with the Oura Membership. New members get the first month free, then it’s $5.99/mo. Register for Oura Membership on the Oura App. Oura Membership is not sold on Amazon. MORE ACCURATE BY DESIGN - Your finger provides the most accurate pulse reading, making your health data and insights more personal than ever. Oura Ring’s research grade sensors monitor over 20 biometrics with precision. SYNC WITH YOUR FAVORITE APPS - Compatible with iOS and Android — Oura seamlessly integrates with over 40 apps including Apple Health, Google Health Connect, Natural Cycles, Flo, Strava, & more. HSA/FSA ELIGIBLE - We can accept HSA or FSA funds for the following: Oura Ring, additional chargers, and shipping. EASY TO WEAR, EVERYWHERE - Every Oura Ring Gen3 is made of titanium: built to last, lighter than the average wedding band, non-allergenic, and water resistant. From a workout to a night out, Oura discreetly monitors your health with comfort and accuracy.