General Aircraft FEATURES Carbon Fiber ANR HEADSET PH-400ACUltra-Lightweight ON / OFF Active Noise Straight Cord Dual Plug Reduction Fixed Wing MP3 Player Interface OVER-THE-HEAD STYLE Noise Reduction Ratings (NRR):29dB HOW TO PUT THE BATTERY ♦ GA use dual plugs. ♦ Active Noise Reduction Ratings(NRR):29dB. ♦ Passive Noise Reduction Ratings(NRR):23dB. ♦ Small AA battery box with belt clip.(Battery not include) ♦ Ultra comfortable faux leather cushions. ♦ Clear Hear performance audio speakers. ♦ Noise-canceling electret Microphone,Dynamic microphone can be optional. ♦ Fu lly adjustable spri ng steel head band. ♦ Low-profile volume control knob. ♦ Earphone Plug: PJ-055(.25"F6.3 phone plug). ♦ Microphone Plug: PJ-068(.206"F5.2 phone plug). ♦ Straight cord from headset to molded plug, 150CM.