The Champion Vanquish Electronic Hearing Protection was designed from the ground up for 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 has active noise cancellation. 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. Bluetoothenabled and have the ability to take and receive phone calls. 12Hour Runtime with Lithium Ion Rechargeable Batteries included with automatic shut off at three hours.