KOSS KEB/24 Stereophones - Blue. The KEB/24 is lightweight with an in-the-ear design for deep bass and listening to music on the go. The KEB/24 features a dynamic element that is positioned just outside the ear for extended frequency response of 15-20,000Hz. The KEB/24 includes small, medium and large silicone ear cushions for a customized fit to enhance isolation when you want to eliminate ambient sounds that interfere with the listening experience. A flexible strain relief has been added for comfort.