The M185 VHF transmitter was worn on the belt of a climber attempting the first ascent of El Capitan in Yosemite National Park by a paraplegic. The eight-day climb was covered extensively by NBC news. Tom Zannes, a New Mexico news photographer and climber freelancing for NBC, climbed alongside, getting spectacular footage and audio. Another journalist, David Jackson, was able to capture the transmitter audio nearly two and a half miles away. The climber, unable to hold himself away from the cliff faces, actually slid up a good portion of the mountain on the transmitter itself, wearing away both paint and metal.
In spite of inclement conditions, icy cold nights and hot days, this transmitter performed without fail throughout the entire climb.