The Impact Pro Earmuff is specially designed for handgun shooters who want superior safety and ear protection. The safety is delivered through distortion-free amplification of low level sounds like range commands. The protection comes from the impressive 30 NRR and instant blocking of noise above 82 dB.The padded headband telescopes to ensure a secure, custom fit. An external audio jack lets the earmuff do double duty as stereo headphones when connected to an MP3 player or other audio source.HIGH NOISE REDUCTION RATING (30 NRR): Designed for handgun and pistol shooters looking for high NRR; perfect for indoor ranges, covered ranges or other extremely loud shooting environmentsAMPLIFIES AMBIENT NOISE UP TO 4X: Built-in directional microphones amplify range commands and other ambient sounds to a safe 82 dB, providing more natural listening and enhanced communicationBLOCKS HAZARDOUS NOISE: Actively listens and automatically shuts off amplification when ambient sound reaches 82 dB; passively blocks out noise at 30 dBCOMFORTABLE, SECURE FIT: Rubberized pressure points prevent gunstock scratching; super deluxe padded headband features telescopic height adjustment for a secure and comfortable fitINCLUDES: 3.5mm connection cord for MP3 players and scanners; includes 2 AAA batteries; automatic shut-off feature engages after 4 hours to help save battery life; approx. 350 hours battery life