SPECIFICATIONS: Drivers: 57mm speaker X 2 Transducer type: dynamic Bluetooth version: V4.1 Frequency range: 2.4GHz-2.48GHz Operating distance: up to 10m (free space) Bluetooth profiles: A2DP AVRCP HSP HFP Impedance: 16 Frequency response: 20Hz-20kHz Sensitivity: 110dB Distortion:<0.1%(THD) Music playtime: up to 40 hours Talk time: up to 45 hours Standby time: up to 1625 hours Charging time: about 2 hours Operational temperature: -10 to 50°C Customized function Audio Sharing allows you to connect to another H headset via an audio cable, and share music with your friends (* it is recommended that headphones with impedance of 32 or higher be used). Simultaneously connect two Bluetooth devices, connect with your phone and tablet seamlessly, and listen to music as you please! Customized function Audio Sharing allows you to connect to another H headset via an audio cable, and share music with your friends (* it is recommended that headphones with impedance of 32 or higher be used). Simultaneously connect two Bluetooth devices, connect with your phone and tablet seamlessly, and listen to music as you please! Iconic powerful bass resonance 57mm ultra-large dynamic drivers, turbine style housing, and Bluedio's iconic surging low-frequency shock let you feel deep bass resonance for superior sound quality.