Based on Shure's popular E4c noise-isolating in-ear headphones, the Shure i4c ($329 list) adds an in-line microphone, a cell-phone switching module, and a Y-cable so that you can take calls while you've got the headphones in your ears. The audio quality is as good as the E4c's, but I can't say I'm impressed with the rather kludgy implementation of cell-phone connectivity. Add to that the inability to control your cell phone via the switching module and the fact that the cables are very thick and aren't swappable for regular headphone cables, and you've got a product that I find hard to recommend, especially for the price. Shure would have done better if it had simply built a $30 attachment for existing Shure E4c headphones.