I was delighted with the sound quality of these earphones. The noise isolation worked really well once I had found the right earpiece (from the wide variety supplied) to suit my ears. There's a big problem though. The plastic sheath around the wire that connects the earpiece to the main cable leading to the jackplug started to fray. First on one side then the other in exactly the same place. The sound then started to crackle and ultimately pack in altogether. I can't find my receipt so I can't get my money back (I know - my fault).
I know two people who bought them and recommended them to me who had exactly the same problem. At least they were clever enough to keep their receipts.
This is the first time I have reviewed a product. Since I can't get satisfaction from Shure I am trying to soothe my frayed nerves by submitting this review to save you wasting your time and money on this product.