Armed with heart-rate and blood oxygen sensors, the Versa 2 is the Fitbit most people will want. Amazon has it for 25% off MSRP.

Image: Fitbit. If you own a Fitbit Charge 3, Ionic, Versa, Versa Lite, or Versa 2, it's time to check the app for a new Estimated Oxygen Variation Graph.

Fitbit has taken the wraps off of its 2020 lineup, including the new flagship-level Sense, the Versa 3, and the Inspire 2. All three offer new features.

The Versa 3 also sports the new PurePulse 2.0 heart-rate sensor as well as on-board music storage and playlists from Pandora and Deezer for subscribers, so you can leave your phone at home.