Bone Conduction Technology Speaker: Create minute mechanical vibrations, send sound to the internal ear through the cranial bones. Release ears, you can hear outside voice while listening to music. Not trapped in the music but stay alert to the surroundings. Giving safety to you CSR Bluetooth V4.1 Chip: Give clearer conversation, lower latency in connecting, stronger and more stable signal, longer working time. Easy and fast pairing with smartphones, tablets and other Bluetooth enabled devices Multipoint Connection: 1 Bluetooth headset connects 2 devices simultaneously, never miss any calls from your devices. Built-in 150mAh battery makes 10 days standby time, up to 4 hours of continuous call/music playing