Internally his heart rate monitor is using an Arduino Pro Mini, a small OLED screen, and a turn-key pulse sensor which was originally conceived as a Kickstarter in 2011 by “World Famous ...

Overall, the Fitbit Versa 4 is a fantastic watch at a mid-tier price of around $199. While there may be more precise (and more expensive) heart rate monitors available on the market, the Versa 4 ...