Volkanox Silenco Series Active Noise Cancelling Bluetooth Headphones (VK2003BK) - Bluetooth Version: v4.0, Range: 10 m, Battery: 300 mAh, Charging Time: ± 3 hours, ANC Working Time: ± 8 hours, Driver Unit: Ø40 mm, Sensitivity: 105 dB/1 mW, Noise Reduction: up to 20 dB, Colour: Black