Military grade dual circuit boards. Gold Connectors for high quality audiophile sound. Automatic shut off and Pro Form Leather ultra comfortable ears seals, and padded, adjustable headband. Amplifies sound more than 8x normal hearing. * Weighs only 11.1 ounces. Fast attack time of 1.5 milliseconds. Includes 2 Lithium 123a batteries. 3.5mm input jacks for i-pod and MP3 players. Battery life is 250 hours.