Swimming

Do you have a link? As a swede I'm intrigued by this.

I found them in the shop. I guess Decathlon’s website might feature them, have you looked? They’re among the cheapest they sell; have a piece of string (going thru a small tube) to join the eyepieces ie you can adjust it loads to fit, and a double looped thin rubber headstrap. Pretty sure they call them ‘Swedish’ or ‘Swedish-style’.