Electronic earmuffs plus shooting glasses for one great price! The Walker's Razor Slim Low Profile Electronic Earmuffs feature a Noise Reduction Rating (NRR) of 23 dB, and utilize sound activated compression (SAC) of 0.02 seconds. SAC is special electronic circuitry that will compress gun shots 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.