The design of the $299 Bose Quiet Comfort II Noise-Canceling Headphones is flawed. The plastic used in the headband cracks under the stress of normal use. We have gone through three sets in two years. Bose replaced the headphones twice at minimal cost to me, but now that the third set has snapped, I'm not even going to bother asking them to replace them again. They work very well and are very comfortable to wear, but the material defect makes them a bad investment.