The Walker's Razor Slim Low Profile 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 Electronic Earmuffs for your next trip to the woods or range. Includes 2 AAA batteries. FeaturesUltra low profile ear cupsAudio input jackLow noise/ frequency tuned for natural sound clarityVolume controlSound dampening composite housingTwo hi gain omnidirectional microphonesRubberized coatingExternal battery door for easy replacementBattery life is roughly 40 hours on high volume and 80 hours on low volume