Sennheiser RS 170 Digital Wireless Headphones (Discontinued By Manufacturer) Connectivity Technology: Wireless Closed circumaural digital wireless headphones Dynamic headphones with clear and detailed audio reproduction Multi-purpose transmitter also functions as an "easy charge" cradle and docking station Multi-receiver transmission for up to 4 people to listen from the same source Dynamic bass and surrond sound listening modes Not compatible with Bluetooth technology The product generates stronger permanent magnetic fields that could cause interference with cardiac pacemakers and implanted defibrillators (ICDs).