This magma helmet has great lines and smooth understated style that lets you just get on with your riding wherever your wheels take you the magma helmet combines looks and performance in a comfortable helmet the advanced rollsys system ars makes sure the helmet is snug and comfortable with a simple turn dial 22 vents keep your head cool and the air flowing even with the integrated big moto inspired visor the weight is kept low so you can enjoy exploring size small 52 56 cm medium 55 59 cm la