The Bluetooth handsfree comes really with a small microphone and it is packaged with solar panel and battery to provide the most portable unit to date. The durable composite resin filling is designed to fit in a hole 2.2mm in diameter and 1.7 mm deep and will pick up sound and vibrations from your mouth to produce incredibly clear sound.

It can perform with all compatible Bluetooth devices with Handsfree and Headset feature. We all use Bluetooth headset but the feature of vibrations from mouth will produce clear sound thinks me of the Bluetooth Mouse set.
Via