Product Description A striking one-size-fits-all bobble hat with bold Mizuno branding featuring Mizunos revolutionary Breath Thermo thermal fabric, which absorbs moisture released by the body to turn it into heat. OSFAHeat Generating Technology Mizunos revolutionary thermal fabric ideally suited as an unrestrictive body layer for extreme winter sports. Exothermic properties allow Breath Thermo to absorb moisture released by the body and turn it into heat. Breath Thermo yarn does more than insulate it generates heat. Using the smallest amount of vapour released from the body.