DAVID CLARK COMPANY INC. > HELICOPTER HEADSETS > DC H20-16PRODUCTS > DAVID CLARK COMPANY INC. > HELICOPTER HEADSETS > DCCI H20-16 DC Helicopter Headset - MODEL H20-16 Special features: Passive / General Aviation NRR: 22 dB Impedance: Standard Earphone Type: Dynamic Noise-Canceling Mic: M-7A Amplified Electret Earphone Impedance: 150 ohms(300 each; wired in parallel) Mic Impedance: 50 ohms +/- 20% Earphone Sensitivity: 90 dB SPL on flat plate coupler, re 1mW input @ 1KHz Mic Sensitivity: 400mV RMS ±6dB into 150 ohm load @ 1kHz for 114dB SPL input Earphone Frequency Response: 200-5,500 Hz Mic Freq Response: 300Hz--3.5KHz per RTCA DO 214 Earphone Plug: U-174/U Mic Plug: U-174/U Boom Type: Universal Flex Cord: 5 ft.Straight Headpad/Hardware: Patented Custom Comfort System Weight/Headset Only: 19 oz.