Features: [9.2mm Dynamic Driver] 9.2mm Dynamic Driver provides crystal-clear sound and enhance bass with excellent depth and detail resolution. [Hands-free Calls] Built-in high-grade Microphone sets your hands free from answering and ending calls during exercise travel. [Three Buttons Line Control] Easy to control playing / pausing music, adjusting the volume, previous / next songs, answering / ending calls. [Comfortable to wear] The in-ear headphone with three sizes of silicone eartips ensure long-wearing comfort and outstanding sound isolation. [Bluetooth Connection] Wireless Bt4.0 ensures transmitting strong signal in high speed. Compatible with almost all BT-enabled audio devices.