Best Headphones~ Black P9 Wireless Headphone, 250gm

Transmission distance: 10m Battery capacity: 400mAh Sensitivity: 105±3db Speaker diameter: 40mm Playing time: about 10h Standby time: about 120h Charging time: about 2h Built-in microphone: YES TF Card:Support Charging port: USB Song switching: Support (short press the function key) Volume adjustment: Support (long press the function key) Answer the call/hang up the call: Support (short press the function key) Audio I/O interface: Support