9mm driver unit MDR-XB21EX headphones with direct vibe structure for superior sound isolation and deep bass, and angled earbud structure for a comfortable fit.
Direct Vibe Structure provides an acoustically-tight seal for superior sound isolation and deep bass sound
Angled earbud structure for stable and comfortable fit
4 sizes of hybrid silicone rubber earbuds for secure fit and long-term wearing comfort (SS, S, M, L)
