AcousticSheep RunPhones Classic Headphones (Royal Blue, Medium) Medium size headband fits most with hat size 6-7/8 to 7-3/8 (21.5 - 23.375 inches) Superior sound with eco-friendly, lead-free electronics Ultra-thin, padded and removable internal stereo headphone system Standard 1/8th inch (3.5mm) audio jack fits most media players Flexible 4-foot stereo audio cord