Enjoy your music with the Sennheiser HDR 120 RF wireless headphones. The Sennheiser HDR 120 RF wireless headphones are an inexpensive supplementary or expansion set, operating in the 863MHz or 926MHz variant frequency range. Specially designed for use with Sennheiser's RS 120 Hi-Fi or television wireless headphone monitoring system, listening music is simply amazing as it is enhanced with extended bass reproduction for Hi-Fi or television monitoring.' These headphones feature extended low frequency reproduction, a supra-aural, open-back design, and NiMH rechargeable battery operation with a 20 - 25 hr. battery life that makes it one of the preferred over the head headphone available in the market today.