Music is your energy for life - the fuel for your heart and soul. Sonic Fuel headphones are specifically designed for active, daily use, to power you forward by delivering extraordinary comfort, style and an immersive listening experience that never sounds artificial, processed or filtered. Just pure sonic goodness for the high-octane tempo of your life. The ATH-CKX9 Sonic Fuel in-ear headphones feature stay-in-place fit, providing unique comfort in addition to optimal sound. The C-tip configuration nestles within the ear where it locks in place for extra stability. Customize your comfort with a multitude of C-tip & silicone ear tip sizes or use the included Comply foam ear tips for true sonic immersion. Large 13.5 mm performance-enhanced drivers fuel your day with a premium listening experience, deeper bass response and sparkling high frequencies. A newly designed flat cable eliminates annoying tangles and lasts longer. The included hard carrying case keeps your headphones protected and organized, so they are easy to find and unravel every time.