Carefully designed headset with excellent passive noise reduction and advanced active electronic noise cancelling technology. Supersoft compact pillow headband and comfort gel ear seals provide extraordinary comfort. M7A noise-cancelling electret microphone,  flex/wire boom for precise, reversible microphone placement, dual volume controls, stereo/mono switchable. Power source  battery case with one 9 V DC battery, battery life approx. 25 hours. Weight approx. 480 g.