" Neodymium magnets Duofol diaphragms for audiophile-grade sound reproductionbr Integrated volume control for enhanced usability conveniencebr Collapsible design with metal-reinforced headband ensures portability durabilitybr Operates for about 50 hours with BA-300 rechargeable battery br Sennheiser SET840 -TV RF Stereo TV Assistive Listening Headphones System"