Device to headphone distance: 10 meters Connection: Bluetooth 4.1 Bluetooth protocol: HFP / A2DP / HSP / AVRCP Ear hooks are soft and flexible. They do not cause pain if wearing them a lot. The left and right earpieces are connected by a wire that goes behind wearer’s neck and does not disturb in training. Suitable for you in different environments, whether it is sweating in the gym, or rainy days of outdoor long-distance running, it can accompany you around.