These are the headphones that with a simple twist convert into stereo speakers. The headphones’ earcups rotate 180°, automatically turning on the built-in, battery powered amplifier and generating crisp sound through 1 1/2" neodymium speakers. In speaker mode, the unit produces up to 98 decibels of sound, plenty of volume for playing music for a room full of friends. When the earcups are rotated back to headphone position, the amplifier turns off. The headphones use proprietary technology that delivers a crisp, clear high-definition listening experience. The earcups’ closed, over-ear design ameliorates external noise and limits the amount of sound that escapes from the headphones, while soft memory foam interiors hug ears for optimal comfort during extended wear. In speaker mode the unit provides up to three hours of music after a three-hour charge via the included USB cable; headphone use does not require battery power. The headphones/speakers connect to any device with a 3.5mm jack. Includes a protective travel case. 8 3/4" H x 8" W x 4" D. (1 3/4 lbs.)