Pyramex Level Dependent Electronic Earmuff PM4010. The Pyramex Hearing Protector has a built in microphone and electronic amplification circuits which can amplify ambient sound for users and will automatically shut down its electronic function when ambient sound exeeds preset safety level (80 dB). An adjustable headband with a soft head cushion is also provided with these earmuffs which provides users a great adjustment and comfort. Features of Pyramex PM4010 Electronic Hearing Protection Ear Muffs Offers electronic suppression of dangerous impulse noises common to industrial users and shooters Amplifies surrounding voices important signals and warnings NRR 30db when used in neutral position Soft head pad for all day comfort Foam-filled padded ear cups fit securely and comfortably over the ear Electronics are designed to limit amplified sound levels to 82db Exceeds ANSI S3.19 Requirements Package Content Pyramex Level Dependent Electronic Earmuff PM4010 Adjustable headband