There are two body sensors that can be used with the device: a heart rate sensor and a speed sensor. The heart rate can be measured by a traditional chest strap, using ECG technology, or by a clip embedded into the headset, which attaches to the ear. The ear clip uses oximetric technology, which can also measure the oxygen levels in the blood. The speed of the runner can be tracked by a small accelerometer embedded into a chip that is tied to their shoelaces. The headset and sensors each contain a Bluetooth module and battery as well.  Once paired with the mobile device, each of the Bluetooth modules creates a secure connection that allows for seamless data transfer across the system.