Sennheiser PXC 550 Wireless NoiseGard Adaptive Noise Cancelling Bluetooth Headph

[Bluetooth 4 2 wireless technology in an ergonomically designed lightweight comfortable and collapsible travel headset perfect for travel NoiseGard adaptive noise cancellation ensures superior sound quality in every environment. Charging time:3 hours Intuitive user control and convenience thanks for voice prompts touch controls NFC pairing smart pause and automatic on/off Triple microphone array delivers business class communications with exceptional vocal clarity. Frequency response (Headphones) - 17 - 23000 Hz. THD total harmonic distortion - <0.5% (1kH 100dB) . Impedance - Active 490 Ω / Passive 46 Ω Sennheiser sound signature quality with selective sound modes to enhance the listening experience.Ear coupling:Circumaural Sound pressure level (SPL): 110 decibels. Codecs - AptX]