Bluetooth Headphone with Built-in Microphone Wireless Bluetooth Headset Retractable Easy Access to Volume for All Smart Phones by ZaxSound Strong Wireless Bluetooth 4.1 Receiver up to 10 meter can Penetrate Through Thin Walls. Easy Access to Volume Control on the Side of the Headphone. Including 3.5mm AUX cord to Connect directly with your phone when you don't use the Bluetooth Function.. Retractable Headband and High Grade Leather. Built-in Microphone, Answer your phone calls with very clear sound.