Blurex Wireless Headphones with Charging Dock (900mhz)-Manufacturer Refurbished REFURBISHED-PACKAGING MAY BE DAMAGED OR REPACKED--900mhz Wireless Headphone Phase-Lock Loop (PLL) technology locks in frequency to prevent signal loss 100 foot range - High quality sound and is virtually interference free Automatic battery recharging on supplied docking station Connects to the audio source via any standard 3.5mm audio jack, no installation required!!!