Nordwestdeutscher Rundfunk-Hiller M59 capacitor microphone, Ser. No. 573, 1953-1955. A single diaphragm electrostatic microphone having nominal cardioid directional characteristics, considered remarkable for its small size. Unlike most other directional electrostatic microphones it employs a metal diaphragm and was claimed to withstand high temperatures--an important consideration in television. The BBC had an M59 in occasional use in the Television Theatre starting in October 1953 and others were employed in the sound service. It had an external low tension stabilizer which was prone to exploding. See studios TI for this microphone. See Inv. No. 2012-5118/498 for stabilizer.