Active noise reduction (ANR)High impedance (civilian aircraft)Built-in ANR rechargeable battery with LED indicator light (10+ hours per charge)Passive / Active Noise locking switchMono / Stereo switchDual volume controlUnit will function as a passive headset when the battery is deadQUICK CONNECT interchangable communication cables (helicopter, fixed-wing, nato, etc)Adjustable gain aviation microphone (5715-CA)22.4 oz (without cord)5 Year Guarantee30-Day Money-Back Guarantee (If you do not like them, return them for a full refund.)Ruggedized Commercial