The perfect travel companion Don't leave home without them. Noise Canceling Earbud Style Travel Earphones reduce outside noise by 92%. Relax and enjoy long operation time (up to 40 hours) with 1xAAA alkaline battery. Compact pen-type design conveniently clips to clothing and features noise canceling switch and slide volume control. S/M/L earpads; air plug; and carrying pouch included. Noise Canceling explained When you hear background noise from an aircraft or car engine; etc.; sound waves are formed.