With two dedicated dynamic drivers, m200 hi fi earphones allow you to enjoy the most delicate nuances of the original recording'. '.strtoupper('c')ombining a 10mm lf driver and a 5.5mm neodymium mf hf driver, kefs unique dual dynamic driver ddd array creates an immaculately detailed and engagingly natural sound right across the frequency range, with the lf chamber connected to the light aluminium housing for tight, resonance free bass'. '.strtoupper('t')he ddd is a full range two way system, pairs a 5.5mm neodymium mf hf unit with a dedicated 10mm lf driver to recapture the clear, intricately detailed and engagingly natural sound of a live performance'. '.strtoupper('t')he secret to its immaculate balance is that the mf hf driver is placed so as to accommodate a port from the bass chamber into the inert cast aluminium chamber that feeds the combined output into the ear canal'. '.strtoupper('k')efs discreet, flexible secure arm folds neatly to the shape of your ear to hold each earpiece in place, even when youre moving around'. '.strtoupper('t')ogether with an ergonomic shell and soft silicone tips that fit snugly over the ear canal to form a tight acoustic seal that eliminates external noise, they feel so natural that you soon forget youre wearing them'. '.strtoupper('c')ompatible with most smartphones, computers and other mobile devices, the m200 has an in line microphone and remote control for iphone and other apple products, allowing you to operate the play functions or switch between calls and music'. '.strtoupper('w')ith the flight adapter provided, its the ideal travelling companion'. '.strtoupper('o')r your comfort and safety, kef headphones are designed to comply with the cenelec standard en60065 a12 for protection against excessive sound pressure.