LAS VEGAS, CES 2013 – Our own Charie Sorrel wasn’t a huge fan of the BodyMedia Fit Link activity tracker when he reviewed it a few months back; negatives ranged from a user-unfriendly app interface and just the overall gawkiness of the device itself. BodyMedia has listened, and addressed at least one of those issues with a smaller, sleeker version of the Core called the Core 2 — and it’ll even allow you to pop the four-sensor device into elegant jewelry designed to accept the, well, core of the gadget.

The sleek tracker records movement, skin temp, as well as “heat flux and galvanic skin response,” the latter often used for measuring stress. And just like other popular trackers like Fitbit and Fitbug, the Core tracks your sleep habits as well.

Like the Link, the Core 2 now uses Bluetooth (in this case, low-energy 4.0) to stream all that recorded data to a free app on your Android or iOS device.  No word on price or release date yet; the original Core is still sells for $120.