Fully adjustable with a comfy padded chinstrap and dial-fit system Formed from EPS foam with an ABS shell. 11 vents Size: S/M 48-54cm (kids and small adult heads) and M/L 54-60cm (adult heads) Fully EN1078 and CPSC tested for your safety Weight: 268g S/M and 410g M/L This simple unisex helmet comes in a tasteful range of gloss colours to co-ordinate with your Bobbin (or not). Fully adjustable with a dial-fit system and contrasting caramel-coloured chin strap, the Starling will let your head breathe with its 11 vents. Formed from EPS foam with an ABS shell, it's fully EN1078 and CPSC tested for your safety. Place a measuring tape around your head. The tape measure should be positioned at the following 3 points: middle of the forehead, just above the ears and the widest point at the back of the head.