Track Heart Rate, Oxygen Levels and Sleep: The award-winning Smart Sock is the first ever baby monitor to track your baby's well-being while they sleep. Worry Less and Sleep Better: be notified from anywhere when your baby needs you by lights and sound through the base station and app notifications on your phone. Proven: uses established pulse-oximetry technology that has been proven both safe and accurate Real-time view: Owletβs free app gives you real-time notifications and let's you see your babyβs heart rate and oxygen levels from anywhere. Available for iOS & Android Fit for Growing Babies: The Owlet Smart Sock fits most infants from 0-18 months or 6-25 pounds, perfect for your growing bundle of joy