Impact Sport blocks impact noise from gun shots and heavy impact noise machines. Impact Sport's patented sound amplification enhances the wearer's awareness of their environment by amplifying ambient sounds, allowing them to hear important communication [co-workers, alarms/warning signals]. Sound amplification volume does not exceed 82 dB - response technology revert to passive hearing protector when noise reaches 82 dB. Slimest cups on the market for comfort when in position of shooting. Provide more natural hearing. Ideal for hearing-impaired workers. Bilsom’s patented Air Flow Control technology delivers optimal attenuation across all frequencies, without increasing earcup size or weight. A patented baseplate chamber and high-tech non-woven layer manage the flow of air inside the earmuff to control how sound reaches the ear. The result is better, more consistent overall attenuation for virtually all industrial noise environments. Air Flow Control is a standard feature on all Impact series earmuffs. Make replacement quick and easy.