Sennheiser HD 660s Audiophile Headphones (B-Stock) - Discontinued desktop the BTR15 also features a

the BTR15 also features a large display - a brilliant 0

MODE 2 Open mode for air circulation through the air hole:  For those who often feel numbness in their ears

Featuring an amber crystal clear cavity

and 768kHz

It could be a nice choice for daily long time wearing too

Sennheiser HD 660s Audiophile Headphones (B-Stock) - Discontinued desktop the BTR15 also features aHD 660S The perfect blend of power and control. The powerhouse open back headphone Connects you to the deepest corners of your music collection. Hi fidelity sound Open back design 42mm transducers Luxurious comfort Detachable cable A Direct Connection To Your Music Known for their engaging signatures and liquid smooth response, HD 660S predecessors HD 650 and HD 600 shattered performance barriers in the audiophile headphone category. The HD 660S