Bose Quietcomfort 3

The headphones come in a handy travel case that can be fitted with a shoulder strap, so when you board a plane, you haven't left them in your other bag. The case also holds a spare battery, the lead to connect to an audio source and an extension, a connector for aircraft that use double sockets (instead of the usual stereo socket), a 1/4" plug adaptor and part of the charger. Bizarrely there is not a space for the other vital half of the charger - the bit that plugs into the wall. The 'phones come with a wide variety of mains plug attachments - the appropriate pins to slot into the charger, and the charger will take any mains voltage, but you have to remember to take the extra bit that doesn't easily fit in the case. I normally just take the shaver socket pins, which work in any hotel room.
The battery takes no more than two hours to charge, and lasts for many hours of use. The manual says 20 hours, and it probably is correct. The batteries are bespoke cells that fit nicely into one of the ear-pieces, so if you can't just buy batteries from shop if you can't recharge them.

The 'phones can be used in two ways:
They can be plugged into an audio source (anything with a 3.5mm jack, or 1/4" using the supplied adaptor. The basic cable is about 1.4m, and there is also a 1.5m extension cable so you can move round the room a bit. It would be useful to have a cable about 0.4m long, for using with an iPod in your pocket, but when I suggested this to Bose, I got a dismissive answer; they don't seem to understand the supplier customer relationship. So I made up my own short lead for this, but it was very hard to get hold of the special plug that goes into the headphones. They don't bother with a volume control, so this is set on the audio source.

Also they can be used simply for noise cancelling, with them switched on but not plugged into anything.

The noise cancelling effect is very good. Just as on-ear headphones they block out quite a lot of noise anyway, but the active noise cancelling does an amazing job of cutting out fairly steady sounds - air-conditioning, the background hubub of an office, and the roar of an airliner cabin. They do less for intermittent noise, so you will still safely hear the phone ring, or somebody shout "Oi, David, stop singing!".

I am not a hi-fi fanatic, but to me the sound quality is very good as well. The 'phones are light and comfortable, and don't get sweaty in the summer. On long flights I wear them unplugged, if I want to sleep.
In common with all Bose kit, they were not cheap, but well worth the money for this special item.