Sennheiser earphone CX300 II 

The CX 300-II Precision in-ear headphones are a great choice for everyday use, offering powerful, bass-driven stereo sound with greater clarity and improved dynamics. The high-quality dynamic speaker system delivers astonishing audio for music, movies or games.
High-quality dynamic speaker systems
Powerful, bass-driven stereo sound
Excellent fit in the ear canal
High attenuation of ambient noise
Three sizes of earbud
Convenient carrying pouch included
Optimised for iPod, iPhone and Mac
Asymmetrical cable