What material are these caps made out of? They look very stiff when the swimmers remove them from over their other caps. it looks kinda like a hard shell. Do they have to be fitted to your own head so they will stay on correctly especially during butterfly?
What material are these caps made out of? They look very stiff when the swimmers remove them from over their other caps. it looks kinda like a hard shell. Do they have to be fitted to your own head so they will stay on correctly especially during butterfly?
