It carries a Noise Reduction Rating (NRR) of 22 in both on and off mode. When the electronic ear protection is switched on, it employs built-in directional microphones that amplify ambient sounds to a safe 82 dB. This allows you to hear important commands on the range and crucial environment sounds when hunting. For additional shooting hearing protection, it also actively listens and automatically shuts off amplification when loud impulsive sounds like firearm discharges reach 82 dB. Patented Air Flow Control technology allows for a slim earcup design that ensures your firearm stock has clearance while shooting. The padded headband features telescopic height adjustment for a comfortable, customized fit. An external audio jack lets you connect the shooting earmuff to an MP3 player, scanner, or other audio source. The battery delivers approximately 350 hours of usage, and the automatic shut-off feature engages after 4 hours to help save battery life. All Howard Leight electronic earmuffs and safety eyewear are compatible for use with each other.