See page 19 of the linked PDF.
I realise this may the hardest to obtain deal I have ever posted but since we have an active deal for Norwegian flights this seemed like a good time to post this.
I was listening to my expensive Bose QC25 headphones on a Norwegian flight recently when turning a page in the menu I almost spat out my cold weak overpriced tea, QC25s for only £179! I paid closer to £250 and I had been waiting for a price drop for ages. I asked the flight attendant and he confirmed I really could have a pair for that price. I seriously considered getting another set but decided against it.
These headphones are incredible on a flight or a train. It's like they lock you in your own cocoon of comfort and tranquillity. You don't have to put the sound up blaring to not hear the engine plus the sound quality is excellent too.