There is a fast growing market for activity and sleep tracking devices, especially for wearable ones, but this little gadget is something else: Fitbit Flex is actually a rubber wristband that is very comfortable to wear and you will never have to take off.

The Fitbit Flex is the latest in Fitbit’s range of wireless activity trackers. It is similar to its predecessor, the Fitbit One, but is not provided with a display. And while previous Fitbit trackers were easy to misplace because of their small size and the fact that they had to be attached to your clothing, you won’t have to worry about that with the Flex.

Fitbit Flex activity tracker

At a first glance, the Flex looks like any ordinary rubber wristband. It is very simple and slim and the only element distinguishing it from other wristbands is the LED lights that give the wearers feedback about their activity stats.

The five LED lights turn on gradually, as the wearer gets closer to their set goals. For instance, if the wearer has set the goal of 10,000 steps in a day, the lights will turn one by one as soon as you complete 20 percent of the task. So as soon as you have made 2,000 steps, the first LED will light up and so on.

The Fitbit Flex can be worn in the shower and it also monitors your sleep, which is yet another reason for not taking it off. The device monitors the duration and quality of sleep and will record how many times you woke up or moved during the night. It is also equipped with a silent alarm feature that vibrates to wake you up at the set time.

Given that it does not have a display, the Fitbit Flex will not show you statistics for your daily activity like traditional tracking gadgets do. Instead, it will wirelessly communicate these data via Bluetooth 4.0 to iOS devices and a limited number of Android operated systems. So far, only the Samsung Galaxy Note II and the Samsung Galaxy S III are compatible with the Flex. The tracker will be sold together with a USB device to sync with a computer, for all those who do not own compatible phones.

Fitbit Flex: The New Activity Tracker in Town

The Fitbit Flex is available in five colors: black, navy, tangerine, teal and slate and can be purchased for $100. Since the tracker can be removed from the wristband, you can purchase a set of bands in various colors for an extra $30.

[Images via uncrate & thrillist]