The Fitbit Aria and Fitbit Aria 2 are scales that you can connect to your PC or smartphone to track your weight. After the initial setup of Fitbit Aria, you no longer need to log in or out to switch accounts.
The Fitbit Aria models are Wi-Fi-enabled smart scales that can measure the user's weight, body mass index (BMI), and lean mass or body fat percentage.
Each scale displays the information on its screen before sending the data to Fitbit’s servers, where it’s synced to the connected Fitbit user’s account. You can view this data in basic graphs and visualizations in any of the free Fitbit apps.
Up to eight people can use the same Fitbit Aria scale. The smart device automatically detects who is using it by comparing their data to the current person standing on the scale.