If you prefer active noise cancelling headphones that will take ups as little space as possible, then the ANC23s are for you. ATH-ANC23 QuietPoint® Active Noise-Cancelling In-Ear Headphones reduce distracting background noise by up to 90% while offering the superior sound that makes Audio-Technica a world-leading pro audio company. Due to their small size, they are convenient to travel with, and come with a small case which includes an airline adaptor and extension cord. It also comes with a AAA battery, which provides upwards of 30 hours of active noise cancellation, and replaceable, various sized rubber buds.