PH-400AC (Carbon Fiber edition) is a limited series of aviation headsets. Which most of the structural elements including shells and their handles, are made of carbon fiber. The use of this material, apart from the unique aesthetics, has reduced the weight of the headphones.(only 9 ounces).Pilot first of all he would feel comfortable, especially after long hours of flights. PH-400AC is equipped with a standard Faux Leather earpads but other types of earpads are also available.