Radians R-3200 Dual Microphone is an electronic sound amplification earmuff. Two independent microphones amplify low sound level noises while compressing sounds that exceed safe levels. Compact folding feature for easy storage. The included 3.5mm stereo input jack and patch cable provides playback from smartphone or digital audio devices. LED On/Off indicator light prevents unintentional battery discharge. Premium adjustable headband with a sleek black color and compact folding design. One pair of the R-3200 ear muffs weigh 0.68 lbs. NRR (Noise Reduction Rating) 23. Fill material: foam