Fitbit's most complete fitness tracker yet (pictures)

The only indicator on the Fitbit Flex is a small array of LED lights. You tap the screen to illuminate them and to initiate sleep tracking mode.

Included in the Fitbit Flex box is the tracker module, a USB cord for charging, a flexible wristband, and a USB Bluetooth adapter.

The tracker module for the Fitbit Flex fits into a pouch on the soft wristband.

Removing the tracker is just a matter of popping open the wristband's pouch.

Wrap the Fitbit Flex's strap around your wrist and fasten its bindings to ensure a secure fit.

It takes a little doing, but once the Flex's strap is attached, the device stays put.

The Fitbit Flex's main tracker unit is the smallest Fitbit device yet.

Once you connect the bundled USB Bluetooth adapter to a PC or Mac, the Flex can enjoy its own private Bluetooth network.

To charge the Fitbit Flex's battery, you must remove it from the strap and then place it with its USB cable charger.