Features: 22 dB Noise Reduction Rating (NRR) Sleek, extremely low profile earcup makes this a very versatile earmuff for most shooting environments Efficient, low-energy consuming with 4-hour shut-off, delivering 350 hours of battery life. AUX jack connects to MP3 players and scanners. Up to 4X amplification makes it easy to hear range commands and conduct conversations, while internal circuitry automatically shuts off dangerous impulse noises above 82dB. Air Flow Control technology enhances the Noise Reduction Rating. Convenient folding headband design for easy storage.