Adjustable jaw length. Head circumference adjustable with a dial. Size S/M (53-56cm) I purchased this used, having used it three times, but I'm selling it because the size doesn't fit. I haven't used it since I bought it. - Photo 1 and 2: There are some areas with minor scuffs and black marks. - Photo 3: The surface of the goggle strap has some cracks, but it can be used without any problems. * Purchases made between February 21st and 23rd will be shipped on the 24th. Please be aware of this. If purchased on the 20th, it can be shipped the same day.