The blue Sony XB Series Extra Bass Headphones are designed for playing back audio from your portable music device. They feature 30mm drivers that are capable of producing a frequency response of 5Hz to 22kHz. The headphones have Sony's Direct-Vibe Structure and pressure-relieving foam earpads that provide noise-isolation and help accentuate bass response. The 1.2-meter flat cord features a serrated finished designed to reduce tangles. The earcups have a swivel-fold design, allowing for collapsible storage.