• Major IV delivers the signature Marshall sound that you’ve come to expect. Custom-tuned dynamic drivers deliver roaring bass, smooth mids and brilliant treble for a rich, unrivalled sound that you’ll never want to turn off.. Driver Impedance : 32 Ω. Frequency Range : 20-20,000 Hz. • 80+ solid hours of wireless playtime with quick-charge capability – only 15 minutes of charging will give you 15 hours of listening. These are headphones truly built for the long haul. • Improved ergonomic design means that when you’re deep diving into your music, the tenth hour is as comfortable as the first. Major IV’s ear cushions are softer to the touch and more faithfully fit the shape of your ear. • 12 Months Local Manufacturer Warranty Store in a cool dry place. China