When I spent 30quid on noise-cancelling headphones, I didn't really know what to expect seeing as most noise-cancellers are excessively-priced.
However don't let the price put you off, these are very capable headphones that go a great job of cancelling background noise. This, along with it's extremely light weight and foldable state make it an excellent pair of portable headphones which I can't do without on my daily commutes on the London underground.
The headphones don't feel cheap either, they're built with solid materials, are reasonably sturdy considering their weight and also come with a fair nice pouch! It's also nice that the noise cancelling is an optional feature so if you run of batteries the headphones won't stop playing either (*cough, im looking at you Bose, *cough). There's also external volume control if like me, you simply just like to shove our iPod in your pocket and leave it there.
So, are these great audiophile headphones? No they're not, but considering their price they produce a very respectable sound quality, are very light and reasonably comfortable, and best of all have respectable noise-cancelling capabilities. At this price you won't regret this purchase.