RAZOR SLIM ELECTRONIC MUFFS - FLAT DARK EARTHThe Razor series feature a Noise Reduction Rating NRR of 23 dB and utilized sound activated compression SAC of 0. 02 seconds. SAC is a special electronic circuitry that will compress gunshots and other loud noises down to a safe level without completely shutting the noise off. This allows you to hear range commands or communicate with your hunting partners even when shots are being fired around you. Features Two Omni directional Microphones Full