(credit: Valentina Palladino)

InBody, a South Korean company that makes comprehensive body composition machines, is now bringing the core of that technology to your wrist with the InBody Band. The daily activity tracker does the usual things—measuring heart rate and steps and calories burned—but also doubles as a “body composition analyzer,” using a quartet of small electrodes to measure body fat. That work has usually been done by bulky smart scales that can measure weight, BMI, and muscle mass; the InBody Band makes body composition measurements mobile.

But the $ 180 Band isn’t perfect—and it raises questions about the usefulness of measuring body fat anywhere and everywhere.

Design: Electrodes all around

The InBody Band looks the way the new Microsoft Band should have looked. It’s a completely curved device, with an LCD display that sits on top of your wrist. Two bioelectrical impedance sensors hug the display module; two more sit underneath it. These shiny little strips measure your body fat and heart rate.