The soundkase keeps your smartphone safely attached to your arm while you run bike workout and more the adjustable neoprene armband comfortably fits small and large arms and is extremely lightweight openings allow for headphones and other cables to be plugged into your device while it stays protected neoprene material breathes well during strenuous exercises and fits comfortably around your arm the soundkase prevents you from having to carry your device or setting it down on workout equipment wh