Howard Leight Impact Pro Passive Earmuffs - The Impact Pro electonic earmuff shooting protection features 30 extreme noise reduction rating (NRR). Rugged earcup design with durable rubberized pressure points. Four hour auto shut-off extends battery life. Single knob control for on/off and volume control. External audio jack connects to any music or audio source; MP3 players, smartphones or scanner radios. Amplifies low-level noise and conversion 4x times louder. Black padded headband with sporty black/gray earcups. Two AAA-batteries and AUX connection cord included. Impact Pro electonic earmuff shooting protection Features 30 extreme noise reduction rating Rugged earcup design with durable rubberized pressure points Four hour auto shut-off extends battery life Amplifies low-level noise and conversion 4x times louder