The Owlet Smart Sock is an ingenious way to give you extra peace of mind. Simply place the Owlet Smart Sock around your little one?s foot and monitor heart rate and oxygen levels from your smart phone! The owlet Smart Sock was designed as Traditional baby monitors don't give parents the information, they need to have peace of mind. The Owlet Smart Sock uses proven pulse oximetry, wrapped in a tiny sock, to track heart rate and oxygen levels. If levels leave pre-set zones, parents are notified immediately. What's new features does the V3 Owlet Smart Sock have? ? New sock design to fit 90% of babies from 0-18months ? Increased Bluetooth range now up to 100ft ? Wireless charging ? 90 Minutes charging time ? Optional "Quick Charge" now an option. 20 minute charge = 8 hour battery life Why do parent's love the Owlet Smart Sock? ? Tracks heart rate and oxygen levels while your baby sleeps ? Notifies you if levels fall outside of a pre-set range ? Proven to reduced anxiety and improve sleep ?