Champion Vanquish Electronic Hearing Protection was designed from the ground up for the shooting sports. Each muff was acoustically modeled on gunshot reports to achieve the optimal balance of all day comfort and noise reduction. They feature Safe Level Sound Compression Technology with a refresh time <1ms. Two Full Dynamic Range HD speakers ensure everything you hear is crystal clear. Omnidirectional microphones pick up everything around you giving a natural sound while minimizing wind noises. – Features & Benefits – Safe Level Sound Compression Technology – Acoustic Foam for All Day Comfort – Sound Refresh Time <1ms – 2 Full Dynamic Range High Definition Speakers – 2 Omnidirectional Microphones – 3x Amplification – 200-Hour Runtime for Models 40978 and 40979 – 3 Hour Automatic Shut Off – AAA Batteries Included