... international standard frequency range Hi-Fi with Calling Wireless Bluetooth Headphone Features:1. Fashion design, made of the ... the end of the call.6. Inner microphone design. Headphone specifications:Button Functions: Volume +, Volume -, the power ... : 100Hz-10 KHzSensitivity:-42dBApplication: with a Bluetooth-enabled audio device, including PCs, mobile phones, MP3, laptop, etc. Bluetooth Headphone