I have owned the Sennheiser RS 120 headphones since 2007. I purchased them refurbished for under $50 from Tigerdirect.

[ getting started ]
Setup was easy. Pretty much plug and play. There is two-prong “block” electrical outlet plug and an audio-in plug (3.5 mm or 1/4”) for your audio device (stereo, iPod, et. Al). I have it hooked into a mid-range ONKYO home stereo. When the unit is plugged in and the audio device is on (i.e., there is a signal), you see a small green light on the headphone transmitter.

To put batteries in the headphones themselves you twist off the ear cushion on one of...