The Withings Pulse O2 is an advanced activity and health tracker. Versatile, it offers all wearing options: slap it on your wrist using the wristband, attach it to your clothes with the clip or simply drop it in a pocket. It tracks your activity all through the day (including steps, elevation, distance, running and calories burned). At night, slide the Pulse O2 in its wristband and launch the sleep cycle analysis to precisely assess your sleep quality. In addition to the daily and nightly tracking, you can also measure your heart rate and your blood oxygen level by putting your finger on the back of the device.