New improved electronic circuitry ensuring even greater dynamic noise compression and extended battery life of over 300 hrs. Deben's new low profile microphone filters reduce wind noise to very low levels.   Reduces noise by 23 dB. Amplifies normal sound levels making range commands more audible and when subjected to impulse noise such as gunfire , attenuates immediately to protect ears. The Deben ear muffs are the best choice for efficiency and comfort