Specifications:-Drive: 40mm-Impedance: 32 OHM-Bluetooth version: Bluetooth v5.1-Bluetooth use frequency band: 2.4GHz-Power level: CLASS II-Bluetooth distance: 10 meters without barriers-Frequency response: 20-20000Hz-With A2DP/AVRCP high-quality stereo audio transmission and remote control protocol-Charging time is about 2.5 hours-The talk time is about 20 hours-Music time is about 20 hours-Standby time is about 250 hours-Battery capacity 400MAH-Charging power supply: TYPE-C interface (computer USB port, mobile phone charger, car charger)-Compatible mobile phones: Compatible with 99% of mobile phones with Bluetooth function on Android, Apple, Microsoft and Symbian systems