Key Features and Benefits: The ultra portable on-ear headphones Comfort zone setting on temporal pad for comfortable, secure fit The ultimate active headphones with a collapsible headband design for protective storage Dynamic element for extended frequency response Oxygen-free copper voice coils deliver deep bass and signal clarity Shop the Koss Red Hot Porta Pro - Headphones - on-ear - wired - 3.5 mm jack at ProBlack in our Headphones & Speakers collection.