With a range of up to 100 metres and a generous battery life, the MDR-RF865RK wireless headset from Sony includes 40 mm neodymium magnets and an ambient-noise reduction feature to deliver clear, powerful sound. It has up to 3 broadcast channels and an automatic frequency search. And with a padded head band and large ear pads, you"ll be able to enjoy all your music for up to 25 hours in total comfort with the MDR-RF865RK wireless headset from Sony!Audio headsets:Diaphragm : 40 mm neodymium driverRange : 100 m