Used both onstage and in-studio by Kygo, the A9/600 headphones use Bluetooth technology with aptX and AAC codecs and are compatible with the Kygo Sound App With the Kygo Sound App, move through Bergen, New York, Ibiza and Los Angeles, experiencing sounds that resonate with the cities that have had a big influence on Kygo's journey so far. With up-to 23 hours of Bluetooth playback from a single 2 hour charge, you'll have your music when you need it most, whenever and wherever! With ultra-soft ear cushions and weighing just 320g, it ensures comfortable use, even for long periods of time. With NFC pairing, these headphones make it as easy as possible for you to connect, listen, talk and enjoy!