The Bluegrass Super Bold is a high quality BMX styled helmet, ideal for all uses, especially for intermediate to advanced BMX riders. BMX & skate helmets are generally designed with two things in mind; safety and style These type of helmets generally arent as aerodynamically designed as other helmets, but what they lack in aero efficiency, the make up with good looks and steeze at the skatepark. FEATURES: Available in 3 sizes: Small (51-55 cm), Medium (56-59 cm) and Large (60-62 cm) As with any helmet its important to get the right size for your head which can be determined by measuring the circumference of your head roughly 3 cm above your eyebrows. Additional sizing information can be found here.