Jawbone's got a new fitness tracker ready to replace its recently discontinued Up24. The $99.99 Up2, available beginning today, slots in between the basic $49 Jawbone Move that can be tossed in your pocket and the $179 flagship Up3 wrist band, which houses additional sensors capable of reading heart rate, skin temperature, and so on. (And yes, it's finally about to start shipping.) But Jawbone thinks this middle device will appeal to the widest range of consumers. It's the new mainstream model.

Designed by Yves Behar, the Up2 is 45 percent smaller than the Up24; it's also smaller than the more feature-rich Up3. Jawbone says it'll last seven days on a charge, is splash-resistant, and can be taken in the shower without any problems. The Up2's sensors are now shielded by an aluminum shell, but aside from this and other refinements to its size and design, you're basically looking at the same essentials that went into the Up24. Jawbone's latest fitness device will track your sleep patterns, daily activity, and it can vibrate to remind you of an alarm or urge you to get moving after you've been sitting too long.

But more than the new hardware, Jawbone is really putting the focus on its smartphone apps and Smart Coach. Smart Coach is the company's health system that offers personalized tips on improving your sleep, diet, and being more active. For instance, if it notices you tend to have a higher step count after a good night's rest, Smart Coach will likely encourage you to head to bed earlier to keep that progress going. It's all a bit more helpful if you're using the Up3, since that fitness tracker also monitors your resting heart rate and can go deeper into analyzing sleep habits thanks to its added sensors. But Jawbone thinks the Up2 will be a fine entry point into greater fitness awareness for many people. You can order one in black starting today at Jawbone's web store, Amazon, and Best Buy. (Best Buy will begin stocking them in stores this Sunday.) A grey model and other color options will follow in the future. With this introduction, Jawbone's device lineup now consists of the Jawbone Move, Up2, Up3, and Up4.

The Jawbone Up2 compared against a similarly priced fitness tracker from Misfit.