Why does the strap not fit around my head?
The strap may not fit around your head if the elastic headband has lost elasticity or if you have improperly adjusted the cinches on the headband straps.
Loss of Elasticity
If the headband fails to return to its original length after pulling the strap in opposite ends, the strap has lost its elasticity. You will need to replace the strap with a new elastic strap.
If the strap fails to secure the device to your head you may need to simply readjust the cinches on the strap to fit around your head. These cinches can both tighten and loosen the strap to fit your head comfortably.