These earmuffs electronically limit loud, harmful noises to 82 decibels and amplify soft sounds up to 19 decibels. Stereo microphones allow you to hear directionally which makes them excellent for hunting and range safety. Independent volume controls on each cup. Runs on 4 AAA batteries (not included). Technical Information Type: Over-the-head Protection Level: NRR = 20db # Reduces incoming noise as much by as much as 19dB. Battery Type and Number: Four "AAA" Batteries Included: No Notes: # Amplifies non-harmful sounds as much as 19 dB while blocking out harmful sounds (such as a gunblast). # Individual On/Off and Volume controls. # Padded headband and soft, foam filled ear cushions # Amplifies the full range of audible sounds up to 100 yards away.