A slim practical slice of silicon beadings allows a secure fit that stays put even through strenuous workouts. Also the adjustable band snugly wraps around your arm or wrist to make your device stay still, so you can focus 100% on your performance Extensive Compatibility & Case Friendly Flexible elastic case is upgraded to work with all cellphones less than 6'' with case on. Easy to put on and take off Used as Armband or Wristband Adjustable strap can be optionally used as either armband or wristband. Two velcro hooks connect even more tightly for a smaller size. Not recommended for slim wrist Non-slip Silicon Beads A layer of silicon beads on panel back keeps your phone safe in place from slips or drops during even high intensity workout Ventilation Design Perforated strap allows air ventilation to stay breathable. Panel vents to keep air flow between your arm and phone for added comfort