The $100 Flex 2 is Fitbit's first waterproof tracker (hands-on)

The Fitbit Flex 2 just might be the most stylish Fitbit we have seen to date.

It's also the company's first waterproof tracker, and the latest in an already large lineup of products that includes the Fitbit Blaze, Alta and newly announced Charge 2.

The Flex 2 is 30 percent smaller than its predecessor, the Fitbit Flex. It's slim, discreet and has long battery life (up to five days). I can't help but be reminded of the Jawbone Up2, which was an old favorite of mine.

The tracker is available now for $100 (£80, AU$130) and will begin shipping towards the end of September or early October. It comes with a rubber strap in both large and small sizes, but the beauty of the Flex 2 is its customization.

The actual tracker is incredibly small, and pops into a new USB charger when it needs a top-off. It can also be used with a variety of accessories, including leather straps, metal bangles and necklaces. There will even be more luxurious bands from designers like Tory Burch and Vera Wang. The actual tracker is incredibly small, and pops into a new USB charger when it needs a top-off.

As for features, it's what you would expect from a Fitbit: It can measure steps, distance, calories burned, active minutes and sleep. The tracker also includes move reminders and can automatically recognize and record a variety of exercises like running and biking.

But there's no heart-rate sensor or a display. The Flex 2 instead features five LED lights (along with vibration) to show step goal, move reminders and even alerts for incoming calls and text messages. After wearing it for a few days, I still get frustrated when I look down at my wrist expecting to see the time. It's slim, but I wouldn't wear it with a another watch.

Part of the reason we like Fitbit's products is for the ecosystem. The Fitbit app is easy to use and has a large social base. The company is also adding a new adventures feature that uses your daily step goal to digitally travel to remote locations, such as Yosemite National Park. It's an interesting concept that we haven't seen before.

The band feels nice and the accessory straps, which start at $15 (roughly £10 in the UK and AU$20 in Australia) for rubber straps and go all the way up to $100 (£75 in the UK and AU$130 in Australia) for the gold bangle, help give it some extra personality. It doesn't have all the bells and whistles of more expensive Fitbit products, but the Flex 2's discreet style and waterproof design will be hard to pass up.

We will have a full review of the Flex 2 in the coming weeks. Stay tuned.