The timeless H10-30 uses an M1 carbon dynamic microphone with variable impedance which makes it particularly suitable for use in aircraft with older radio or intercom installations or to ensure compatibility with other dynamic microphone headsets. All other features – adjustable headband and hinged mic boom, volume control and gel ear seals – are all classic David Clark. Arguably D-C’s best value headset, NNR 24dB, weight 540g.