content: These are made by Sennheiser, so expect great sound quality, especially for in-ear buds.However, where these lack is in construction. There are so many little parts to these headphones that you invariably lose pieces. The rubber on the ear phones are customizable so they fit to your ear. They also fall out and get lost easily; currently, I have two differing sizes between the two ears because I've lost the right sized ones. The little plastic extrusion that juts off the top also has a rubber piece that is easily lost.Bottom line, these headphones are probably great if you never move them (say, only use at desk). But if you're like me an work out with them, use them for commute, there is little doubt that the headphone you have in two months won't be the one you have today.