New Owlet Smart Sock 3rd Generation Baby Monitor (Mint). Never opened - never used. Compatible with WEB APP version of Owlet App. Use the Sock to track your child’s heart rate, oxygen level, and sleep trends from the first night you bring them home to their first day of school, and enjoy peace of mind through every milestone. View your child’s readings in real time with the free Owlet App and receive notifications if readings leave preset zones, so you know when your child really needs you.