The Sony MDR-AS100W are earbud style headphones at the top of Sony's Sports and Active Style line. The headphones feature a shock absorbing mechanism to prevent noise transfer and are water resistant making them suitable for sports. They also feature a moisture guard mechanism which pulls sweat away from the ear canal. The MDR-AS100W have 13.5 mm driver units with Neodymium magnets which combine to provide clear sound and powerful bass. The are designed with an ultra-light slim band which makes them very lightweight, at only 25 grams (excluding the cord), with a gold-plated straight stereo plug. They have a 2 ft cord which makes it possible to use them with an arm-band as well as a 2 ft extension cord. The MDR-AS100W come with a hard carrying case and 3 sizes of earbuds for an adjustable fit.