Owlet sock baby monitor (1st Gen) - this is the 1st genaration version of the fantastic dream sock, that can monitor baby heart monitor and oxygen level. It's a small sock that you can put on the baby's feet, and there is a app for your phone that monitors that data wirelessly. There are settings for notification when the rate or the oxygen levels go below any amount. There are three sizes of the sock, for newborn vs slightly older, etc. I can tell you as new parents, this provided us with a huge peace of mind that when the baby was sleeping, everything was OK. There are newer versions of this, that have a lot more features, but the most important is heart rate and oxygen levels, which is enough to tell you that everything is OK, and this being the 1st gen, it comes at a fraction of the cost. Bid now, and keep your baby safe!!