The Howard Leight Impact Sport Electronic Earmuff features a super-slim earcup that makes it ideal for most environments. The cutaway at the bottom of the earcup is specially designed to provide firearm stock clearance while aiming. Two high-gain microphones deliver 4X sound amplification of range commands or forest noises for excellent situational awareness. The mics are also omni-directional to let you know exactly where sounds are coming from. Hearing protection is ensured as the electronic earmuff actively listens and automatically shuts off amplification when loud impulse sounds like gunfire reach 82 dB. It carries a Noise Reduction Rating (NRR) of 22 in both on and off mode. The padded headband features telescopic height adjustment for a comfortable, customized fit. An external audio jack lets you connect the earmuff to a music player, scanner or other audio source. The battery delivers approximately 350 hours of usage, and the automatic shut-off feature engages after four hours to help save battery life. All Howard Leight safety earmuffs and safety eyewear are compatible for use with each other.