Pro-Amp electronic muff a full function electronic earmuff with an affordable price. Automatically compresses harmful impulse and continuous noises to a safe hearing. Enhances low level sounds to allow better hearing. Forward facing dual microphones provide accurate directional pinpointing of sounds. Independent volume controls for each microphone. Pro-Amp behind the head electronic NRR21 the head wire earmuff eliminates interference while wearing your favorite hat, comfortable, low profile design will not interfere with gunstock or equipment. Outfited with microphones to pick up and amplify low level noises, dual microphones with independent controls.