... output voltage: 250mVRechargeable Li-Po battery,900mAh(built-in in headphone)Power Supply:230V plug-type power adaptor(for transmitter) Input ... be operated via standard batteries Contents:Base station,Headphones,2xAudio cables(1.5m),jack plug adaptor (6.3 to 3.5mm ... ),power adaptor Material:Housing,Plastic,Ear cups,EVA foam with fabric cover Instructions for use enclosed High frequency headphone