Fitbit's Flex is a first-of-its-kind, activity tracking wristband that syncs wirelessly on-the-go via Bluetooth 4.0 to select iOS and Android devices.

Like its sister products the Fitbit Zip and Fitbit One, the new Fitbit Flex tracks steps taken, distance travelled, and calories burned, as well as a brand new stat: active minutes. Active minutes track how many moderate-intensity cardio minutes you have a day (the Center for Disease Control recommends 150 of them each week). Flex’s bright LED indicator lights offer a visual display as you reach 20 percent increments of achieving your goal (such as walking 10K steps), while a vibrating notification celebrates with you as you hit your goals throughout the day.

Flex also tracks how long and how well you sleep, allowing you to learn how to sleep better. It offers a Silent Wake alarm that gently vibrates to wake you without waking your sleep partner.

The Flex is apparently the first and only activity and sleep tracking wristband on the market to sync with Bluetooth 4.0, so you can view your Fitbit dashboard, receive motivating notifications and engage in fitness competitions with friends without ever having to plug in or even push a button. The wristband is comfortable enough to wear all day and can brave the elements as its water-resistant.

Bluetooth 4.0 syncing works automatically with select iOS and Android devices, including the iPhone 5 and iPhone 4S, as well as the Samsung Galaxy S III and Samsung Note II. The iPhone and Android app and online tools show activity charts, leaderboards and more.

You can set goals, view progress and earn badges. You can also log food, weight and more on Fitbit’s website and apps. Fitbit also integrates with many popular health and fitness apps, including Endomondo, LoseIt, MapMyFitness, MyFitnessPal and Sparkpeople, to enable users to share data from their favorite apps.

The Fitbit Flex costs US$99.95 and is available now at Fitbit.com and at major U.S. retailers. It comes with a flexible, interchangeable tracker with a variety of colorful wristbands (black, slate, teal, tangerine, Navy) that allow you to personalize your Flex. Flex trackers are sold with black or slate bands, and users can purchase accessory packs (teal, tangerine, navy) for $29.95 for all three or $14.95 for one color.