From Headphone Bar: *update - in stock & the adjustable ports really work well. Feels very well made, not luxurious, but certainly built to last. Perfect size so they're comfy and have plenty of room for your ears, but are small enough and fit close enough to the head that you'd have no problem wearing them out of the house. 5' cable.

For most people, this is ta great do-it-all headphone.

Their innovative design incorporates ports in the rear of each earcup and a sliding cover. By uncovering more ports you retune the headphone to provide more bass and an airier sound. If you want max isolation, just cover the ports. A bit more bass, slide it open a touch. With good isolation (-no batteries to change or electronics to fail, unlike noise cancellation phones), user adjustable bass response and the best construction/build quality available at this price, these will fit the needs of many listeners.

You can customize the appearance by buying new trim pieces and replacing the stock ones. There are a variety of accessories being rolled out very gradually, including different cables, a gaming mic, trim plates and shields with different designs.

Reviews:

Headfonia.com - They like them alot.

From Beyerdynamic: The CUSTOM series represents an entirely new concept which transforms the experience of listening to music via headphones into an interactive event. Thanks to CUSTOM sound, CUSTOM style and the CUSTOM cable, the headphones can be adapted at any given time to any given requirements – providing an all-in-one solution for almost any scenario.