The David Clark H10-13H headset is guaranteed to be the most comfortable headset you will ever wear. The H10-13H Helicopter headset from David Clark still returns a noise attenuation of 23dBs and is extremely lightweight. The H10-13H has a newly designed headband with soft-foam air-flow pillow assures comfort and eliminates hotspots. It retains all the superb quality engineering you've come to expect from David Clark. Supporting the standard quality and performance features you expect. Like the H10-13.4 this helicopter headset has the exclusive M-7A microphone (flexible boom) and a noise reduction rating of 23 dB for clear communication both ways. The headband does not put pressure on your head like other pilot headset brands and the unit has gel ear seals that are undercut to fit comfortably around your ears. The only difference is that this variation of the headset has a five foot coiled cord that terminates with a U-174/U plug for a helicopter. David Clark H10-13H Headset Specification Impedance: Standard NRR: 23dB 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: PJ-055 (.25" phone plug) Mic Plug: PJ-068 (.206" phone plug) Boom Type: Universal Flex Cord: 5 ft.Straight Headpad/Hardware: Super-Soft, Double-Foam Headpad,Lightweight Hardware Weight/Headset Only: 16.5 oz. (468 grams)