The Ultrahuman Ring AIR is designed for comfort and performance, featuring an ultra-lightweight, notch-free design that you'll barely notice. It acts as a comprehensive sleep tracker, monitoring your sleep stages (REM, Deep, Light, Wakefulness) and providing actionable insights to improve your rest. The 'Movement Index' encourages daily activity for better glucose metabolism and increased non-exercise energy expenditure, tracking steps, workouts, and calories. Its Workout Mode offers detailed insights into your cardiovascular response and training intensity by monitoring heart rate. The 'Dynamic Recovery Score' assesses your recovery by analyzing sleep, heart rate variability (HRV), and skin temperature, updating in real-time based on naps or other recovery activities. Crafted from space-grade titanium with a carbon coating, the Ring AIR is both durable and comfortable, boasting a minimal form factor for precise health monitoring. It also includes features like PowerPlug for heart rhythm monitoring (detecting AFib), habit reminders (Vitamin D, caffeine, screen time), VO2 Max tracking, and menstrual cycle tracking. The ring charges in 90 minutes, offering up to 6 days of battery life, and is waterproof. It weighs only 2.4 grams, making it the lightest smart ring available.