Size - ( fits 19" - 22" circumference )
generally fits adolescents and petite adults
Size 0 ( fits 22"-24" circumference )
fits most adults
Size + ( fits 23" - 25" circumference )
fits most adults who prefer a bit more allowance when wearing as a neck gaiter or headband. Also usually preferred by those with thicker hair.
When worn as a hat, the Versa Toque is meant to fit as a slouchy beanie.