PRO-AMP 23 A full-function electronic earmuff with an affordable price. Automatically compresses harmful impulse and continuous noises to a safe hearing range below 85 dB while still allowing normal sounds to be heard without clipping or cutting. Enhances low level sounds to allow better hearing. Forward facing dual microphones provide accurate directional pinpointing of sounds. Independent volume controls for each microphone. Two easy-access external battery compartments hold 3 AAA batteries each for long lasting use (approximately 280 hours). Batteries are included. Adjustable headband for comfortable fit. Includes a set of replacement microphone covers. Collapses for easy storage. Meets or exceeds ANSI S3.19-1974.