Sony 3.5mm In-Ear Clip-On Portable Stereo Sport Headphones (Blue) Open-air headphones clip into the ear via a vertical design Non-slip design is perfect for active pursuits like exercising and dancing 13.5 mm diameter driver used for small size and delivery of deep bass Neodymium magnets provide maximum energy with minimal size Tangle-free cord (3.5 feet) is adjustable and stores away in backpack or purse