Don't think anybody from the etymotic company hangs out here (I did tell their service manager about AC) but if anybody is considering buying the product, I want to endorse them wholeheartedly. They replaced my hf3's even though their problem was pretty clearly my fault. In fact, when I spoke to their service manager, he basically implied that as long as I hadn't cut the cable into one-inch pieces, they would most likely replace them. We live in a hard nosed age and many companies would have told me "Sorry Charlie", which Ety would have been perfectly justified in doing. Not saying they would do this every time, for everybody, but they are obviously a company that cares about the customer, not just the almighty buck.