Compact size and lightweight, easy for carry Using 4.0andEDR Bluetooth technology, stable signal transmission, low power consumption Support call answering, voice navigation and voice calls functions Large button design, the best choice for male riders Built-in high-quality anti-interference microphone, high sound fidelity Built-in high-quality headphone speaker, strong bass, clear mid-range, high-pitched sound With Micro USB charging interface for quick and easy charging Built-in 180mAh lithium-ion battery, long standby and working time Specification: Bluetooth version: V4.0 and EDR Frequency range: 2.4026GHz-2.480GHz Transmission distance: 10M (transmission distance due to environmental factors and mobile phone Bluetooth devices are different) MIC distance: 1 meter Lithium battery: 3.7V or 180mA Charging time: 2-3 hours Standby time: about 160 hours Continuous working hours: about 8-10 hours Thickness of earphone: 1.1cm Diameter of earphone: 4.5cm Length: 21.5cm Package included: 1 x BT8 Motorcycle Helmet Bluetooth Headset Wireless Earphone Hands-free Speakers Music Headphone 1 x Charging Cable 1 x English User Manual Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement.