Good news wearable enthusiasts: Fitbit just announced its latest fitness tracker, the Alta HR (starting at $150; nordstrom.com, target.com, and other retailers). OK, it isn’t exactly new; it’s an update to the original version, which launched in 2016. Still, after testing it for a week (on the ski slopes, in boot camp classes, during runs, and for general daily life dealings), I must admit that I am impressed. I like to think of it as the little sister to its predecessor—same great genes, but just a little spunkier.

In the market for a new device? Or, just trying to decide whether or not you should upgrade? Here’s the scoop.

The look: According to the folks at Fitbit, this tracker is “the world’s slimmest wrist-band, continuous heart rate tracking device.” Basically, that boils down to you don’t need a big old clunky heart rate monitor, because this sleek version has got you covered. The original snap closure band is gone, and has been replaced by a more traditional buckle style one. You’ll also notice that the colors of the interchangeable bands include slightly different hues this time.

New standout features: If you haven’t figured it out by now, the HR stands for heart rate. And, yes, this mini device is continually recording your ticker all day long, giving you access to everything from your resting heart rate to those zones during your sweat sesh (peak, cardio and fat burn) in real time.

Also handy: the new Sleep Stages feature. While it has been announced, it hasn’t been pushed through to the Alta HR just yet. (If you own a Blaze and Charge 2 you’ll also have access to this feature when it officially launches later this spring.) But here's the gist: It’s going to use that heart rate it’s been continuously monitoring to help estimate the different stages of your sleep (light, deep, and REM) along with how often you wake up mid-snooze. The result: a better understanding of your sleep quality. This data will help you with your overall Sleep Insights, another new feature, that will offer personalized guidance on how to improve, yep, you guessed it, your zzz's. Bonus: It also shows the slumber trends of folks your same age and gender.

But my absolute favorite feature is a longer battery life. In fact, the battery can last up to seven days on a single charge (that’s 40% longer than its predecessor), which is amazing for people like myself who are notorious for forgetting to plug in their gadgets nightly.

The bottom line: The Alta HR gives you cool features of a smart phone, like email, text and calendar notifications, in a streamlined silhouette that also auto tracks your runs, keeps up with your ticker and helps you sleep better. And if we are doing size comparisons, it is 25 percent smaller than the Fitbit Charge 2. My vote: thumbs up all the way!