BackBeat Pro reference earphones satisfy the demands of studio engineers and professional musicians with armature micro-speakers delivering high-definition audio, superior noise isolation and exceptional comfort. High-Definition Audio -Professional tuning and design create stage and studio quality sound from a single balanced armature -Musician-grade reference quality sound. Custom Fit -Superior passive noise isolation -8-piece fit kit with multiple ultra-comfort neoprene ear tips plus one set of dual flange tips for extra noise reduction.