A printable version of the Fitbit Flex user manual is available on the official Fitbit website, as of 2015. The website also offers user manuals for other Fitbit models.
Users can visit Fitbit.com, click the word Help in the top menu, and then click the word Product Help. Clicking on the Flex icon brings up the Web page. Click the Flex product manual link, and the manual appears in the browser window. Then print the manual using the print function of the browser.
The Fitbit Flex has many features, including a battery that holds a charge for up to five days. It is also water resistant and can sync to a Fitbit account via a mobile phone.