With the NoiseGard ™ system, Sennheiser has come up with an effective solution. These operating instructions explain the NoiseGard ™ principle and show you how to use the NoiseGard ™ headset. Noise levels 140 dB Jet engine (at a distance of 25 m) 130 dB Aircraft engine (This is the treshold of pain) 120 dB Pneumatic drill 110 dB Blacksmith's hammer, concrete works 100 dB Die-cast machine 90 dB Metal workshop 80 dB Tractor 70 dB Office 60 dB Conversation 50 dB Ambient noise 40 dB Living room 30 d

self-adhesive piece of velcro . MZQ 2002-1 Supply schedule 1 HMEC 25-KA or HMEC 25-CA 1 Carrying case 1 wind-shield MZW 45 (Art.No 75823) 1 self-adhesive piece of velcro, fig. . 1 MZQ 2002-1 clip (Art.No 44740), fig. . 16 17 Technical data NoiseGard ™ HMEC 25-KA / -CA Headphone Transducer principle dynamic, open, supra-aural Frequency response 16 Hz - 22 kHz Impedance active/passive 200 . (mono) 400 . per side (stereo) same volume for active and passive THD < 1 % Compensation active and passive