535. Take good care of them, they feel robust but they are small so can get damaged. Also there are some Chinese counterfeits out there, in common with many top of the range items. This is now sold with a Bluetooth option you can swap into, which is fine for blocking background noise, movies and iPlayer, but as with all BT, you lose too much on the sound spectrum when it comes to music, so it's best to swap back to wires for that.