BEWARE of the knockoffs. Not all phase change technologies are the same.

Knockoffs can only make small packs at 65F.
Knockoffs can't make anatomic shapes.
Knockoffs don't make other temperature products.
Knockoffs can't deliver maximum cooling time.
Knockoffs don't have the sealing technology
Knockoffs can't vary temperature for situation/task
Knockoffs don't have blunt force energy protection