David Clark Headset H10-13.4 U174

Features: 

• Expanded, super-soft, double foam head pad 
  
• Larger, yet lighter, Comfort Gel, undercut ear seals 
• Reduced headband force
• Universal flex boom for perfect microphone placement
• Exclusive M-7A, the most advanced noise-cancelling microphone available 
• Low-profile volume control knob with detent settings
• Molded cord assembly made to exceptional pull and flex standards
• 5-foot extended coil cord
• FAA TSO Approved C57b, C58a
• Exceeds RTCA/DO-214 Standards
• Weight (without cord assembly): 16.5 oz.
• Certified Noise Reduction Rating - 23 dB
• 5 year warranty

Specs:

• Ear coupling: around-the-ear
• Hardware: steel
• Connector type: U174/U
• Connection cable: approx. 5 ft. (1,5m) coil cord
• Weight w/o cable: approx. 16.5 oz. (488 g)
• Dome type: ABS
• Characteristic SPL: approx. 95 dB SPL (1 kHz, 1 mW) @ maximum volume nominal
• Contact pressure: approx. 0.6 lb. (2.7 N)
• Total harmonic distortion (THD): < 1% - 110 dB SPL (300 - 3,000 Hz)
• Transducer principle: Dynamic
• Ear Impedance: 150 ohm (300 each; wired in parallel)
• Ear Freq Response: 200 – 5,500 Hz
• Microphone principle: M-7A Amplified Electret
• Mic Impedance: 50 ohm +/- 20 %
• Mic Sensitivity: 400 mV +/- 6 dB into 150 ohm load at 1kHz for 114 dB SPL input
• Mic Frequency Response: 300Hz – 3.5KHz per RTCA DO 214
• Mic DC Supply Voltage: 8-16 V, not polarity sensitive
• Source Resistance: 470 ohm