Our Gel Defenders are designed to aid in the protection of head injuries while using approved helmets.
While worn under a baseball cap or cowboy hat they offer some protection as well.
If you cool or heat the Gel defender before using they will retain the temperature for a period of time.
Depending on the temperature you make the Gel Defender to and depending on outside temperature comfort may last about an hour.
Some studies have been posted .
Sizes S, M, L and XL fits hat sizes from 6 to 8".