Sennheiser CX 300 Headphones (Silver)

Pros: Moderate price, good noise isolation

Cons: Mediocrate sound, lack of accessories

Summary: I bought these earbuds for long flight. Recently I used Koss The Plug, Sennhesier MX400 and PX200, and the factory earbuds of Sony Ericsson W800i Walkman mobilephone, so I have a number of comparison.
Phisically it's the same type as W800i earbuds, with the 3 silicon flange. For the first try the default flange fits well in my ear canal, but after several hours of wearing it could be a little uncomfortable.
Sound quality is acceptable, however worse than PX200. I expected more based on the reviews. The bass boosted too much, the middle "canned" and the treble is a bit weak, the overall impression is not clear enough. The volume is ok. So I rate it mediocrate sound quality.
The isolation of ambient noise is ok, it fits to my expectations.
The wires seems a bit too thin to me and it makes friction noises in my ear while rubbing on my clothes.
I don't like the long and asymetrical wires, it always makes me trouble how I organize it. (I don't understand why they don't have a version with shorter cable?)
The lack of carrying case or pouch is a pity.
Summary: for 50 bucks you can have a good passive noise isolating earbud if you are not a kind of audiophil.