Built-in directional microphones to amplify range commands and other ambient sounds, a safe 82 dB, provides more natural hearing and improved communication. It offers the ultimate in safety and ear protection. The safety is delivered through distortion-free amplification (up to a safe 82 dB) of important low level sounds like range commands and conversation. Designed for use in the field or in the field, these earmuffs also feature low profile ear cups that do not interfere with when aiming. An external audio jack allows the earmuffs to do double duty as stereo headphones when connected to an MP3 player or other audio source. The design of the rail adapter can rotate 360, so you can easily put the earphones away. Rail Adapter can be used on full range of FAST helmets,ACH helmets,MICH helmets,etc who have ARC rails on side. Package: 1 x headset 1 x Connection line Note: headset does not include helmet