Over-Ear Wireless Headphones. Features: Charging station also usable as a holder. Padded and flexible ear cushions for ultra portability. Volume control and power button with LED indicator. Three transmission channels for avoiding inteference, other radio sets in the living area can therefore not interfere when you listen to music. Great frequency stability due to the PLL system for optimal transmission. Range: up to 100 m in open space, approx. 20 - 30 m in buildings for much freedom of movement. Run-time with medium volume: 8 hours. Sensitivity: 107 dB. Speaker Diameter: 40 mm. Frequency Range: 20 Hz - 20 kHz. Impedance: 32 Ohm. Colour: Black.