A combination of bass boosting technology and powerful driver units delivering quality audio with a punch. The HA-FX21BT is ideal for music on the move.Being both splash and sweat proof (IPX2) including the 3-button in line remote you can Play/Stop/Skip music and adjust volume easily. The built-in mic is convenient for hands-free calling. Transmission Area -Approx. 10m Driver Unit - 8.2mm Magnet type - Neodymium Frequency Response - 20-20,000Hz Power Supply - Built-in rechargeable battery Battery Life (approx.) - 5 hours (with 2.5 hours of charging time) Weight (without cord) - 11g 3 button operation - remote (via Bluetooth), volume +/-, power Bluetooth version - 4.1(class2) Bluetooth profile - AVRCP, A3DP, HSP, HFP Supporting codec - SBC Accessory - S/M silicone earpieces, USB charging cord