The CROMO NCX-100s are our most advanced noise cancelling headphones. With these headphones you will enjoy superb quality Hi-Fi sound without the distraction of annoying background noise. Perfect for use when travelling on planes, trains, or in a noisy home or office, the NCX-100 have been designed to deliver accurate sound reproduction over a wide range of musical tastes, whether in passive, noise cancelling or bass mode. For portability the headphones fold up and can be stored in the supplied, tough carry case. Key Features The noise cancellation circuitry uses 4 built-in microphones to remove up to 95% of external, ambient noise. Additionally a built in 5W amplifier incorporates a switchable bass boost circuit that can be used in conjunction with the noise cancelling to provide 10db of bass boost. For convenience, the headphones can also be used in passive mode without the need for battery power. External Reviews As reviewed by Crowded Brain, August 2013. CROMO NCX-100 received a 90% rating by Crowded Brain. Some comments included: \'...the noise cancelling technology certainly worked and allowedus to comfortably listen to our music...\' \'...the two modes provide a boost in audio output with a lovely tone to match.\' \'...one of the most comfortable headphones we have ever used.\' Click here to read the full review A short review is also available on the Dadblog UK blog... Click here to read. Package Contents CROMO NCX-100 Noise Cancelling Headphones Rigid carry case 1.4m audio cable with built-in microphone In-flight and 3.5mm to 6.3mm stereo jack adapters User manual