C5 noise-isolating in-ear headphones bring you amazingly natural acoustics and fit so comfortably and securely you'll hardly be aware you're wearing them. Bowers & Wilkins unique Micro Porous Filter system makes sure that sound is open, spacious and full of rich, lifelike detail. So you can truly lose yourself in unadulterated sound, even when you're on the move. They feature Bowers & Wilkins innovative Secure Loop design - loops of plastic-coated wire that curl around the inner rim of your ears and hold the in-ear headphones firmly in place. The C5s are also Tungsten Balanced, meaning that the headphones are weighted towards your ears, rather than away from them, for optimized noise isolation. If you want a spacious sound, you need room to breathe. Not a problem for a large speaker, but quite a challenge for a set of headphones small enough to fit in your ears. With C5 in-ear headphones, Bowers & Wilkins engineers got around the problem with the Micro Porous Filter. Hundreds of microscopic steel balls act as a sonic diffuser, opening up the sound and making music feel remarkably rich and expansive