Features: - High Definition built-in microphone - Standby time up to 75 hours - Continuous usage time: up to 8 hours - Frequency response: 20Hz - 20 KHz - 40mm neodymium speaker driver and impedance 32 ohms - Rechargeable lithium-ion battery: 3.7V 300mA - Charge through computer USB interface/ output DC5V/ 500mA charge Specifications: - Speaker diameter: 44mm - Sensitivity: 108dB|3dB - Cord length: 1.5m - Cable type: PVC - Plug: 3.5mm gold chrome What's in the box 1 x Headphone 1 x Charger