These inner ear headphones are made possible by SONY’s unique closed vertical-in-the-ear design, which vertically aligns the 16 mm driver with the ear channel. The lightweight, highly rigid magnesium case is integrated with the driver unit, suppressing excess vibration while also achieving high-quality sound and a compact size. The newly developed “flexible ear hanger” makes the cord adjustable by tucking it behind the ear. This addresses the issue of the headphones falling out occasionally. The detailing is done in an aluminum material which gives the model a premium feel.