Howard Leight by Honeywell Impact Sport Sound Amplification Electronic Shooting Earmuff, Classic Green (R-01526) Built-in directional microphones amplify range commands and other ambient sounds to a safe 82 dB, providing more natural listening and enhanced communication Actively listens and automatically shuts off amplification when ambient sound reaches 82 dB; Noise Reduction Rating (NRR): 22 Features low profile earcups for firearm stock clearance; adjustable headband for secure fit; compact folding design for convenient storage; classic green color Includes AUX input and 3.5 mm connection cord for MP3 players and scanners. Integrated power/volume knob Includes 2 AAA batteries; automatic shut-off feature after 4 hours increases battery life; approximately 350 hours of battery life; works well and long with Polaroid AAA Batteries