Koss Fitbuds in blue. Koss" female designers teamed up with Dara Torres to design the first headphone series for women by women. Koss Fitbuds bring Great Sound to listeners in earbuds that are only six millimeters in diameter, making them 33% smaller than average earbuds. The elements are surrounded by a soft-rubberized housing to fit perfectly in female ears. The Fitbuds feature a sweat-resistant coating, five color options, and extra cushions. Covered by a Limited Lifetime Warranty on line at Koss.com or 800-USA-Koss.