About Hisonic : Hisonic is short for HI-FI Sonic. A team that specializing in designing and developing ,manufacturing High quality High cost-effective , HI-fi audio products including microphones, speakers, headphones, was started by 13 young university graduates in year 1996. Our brand had already been registered on china,hongkong and european union,usa.Specifications Bluetooth version: V5.0 Volume limited: 93dB Play time: up to 15 hours Bluetooth connection distance: up to 10M Charging time: 1-1.5 hours Battery capacity: 250mAh Impedance: 32 ± 5? Driver diameter: 30mm Frequency range: 20-20KHz Microphone: microphone function support Connections: 3.5 mm Cable length: 1.2M Product Weight: 148g * 2 Package: 24 * 22 * 7