The Walker's Razor Patriot Send It Electronic Earmuffs 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 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. Your hearing cannot be replaced, so make sure you pick up a set of Walker's Razor Patriot Send It Electronic Earmuffs for your next trip to the woods or range. Includes 2 AAA batteries. FeaturesOmni Directional MicrophonesLow Noise/Frequency Tuned for Natural Sound ClarityFull Dynamic Range HD Speakers for Clear Balanced SoundSound Activated Compression 0.02 Second Reaction TimeSound Dampening Composite HousingSend It Patch IncludedAudio Input Jack2 AAA Batteries Included