900 MHz wireless technology transmits audio signal through walls, floors and ceilings at distances of up to 150 ft from transmitter.   Freedom to move around—no line of site required.   Convenient volume controls on headphones.   PLL technology locks in frequency to prevent signal loss.   Sound is always clear.   3-channel transmission to reduce frequency interference.   Induction charging allows for no cable connection for fine adjustment on the docking station.   Inductive charger is connected to an AC/DC power source and transfers energy without making direct electrical or mechanical contact to the inductive receiver.   Headphones get recharged as soon as placed back on the charger.   Adjustable headband and velvet earpads provide soft, comfortable fit.   Includes rechargeable AAA batteries.