The Bell 4Forty AIR MIPS helmet has 15 ventilation openings and is made from a Fusion In-Mold polycarbonate shell.Features:- Designed for MTB- Weight: 380 g - 15 openings - Complies with US CPSC safety standard. - Fusion In-Mold polycarbonate shell - Fit system: Float Fit- Adjustable visor system Goggle Guide- Padding with anti-sweat guide- Flat belt fastening system Technologies:- MIPS systemLeading technology in flat displacement inside the helmet, designed to reduce rotational forces that can result from certain impacts. When the head rotates rapidly and comes to a sudden stop, the rotational acceleration can cause high levels of stress in the brain tissue. The tissue strain caused by these movements can result in various types of brain injuries. We believe that helmets equipped with MIPS technology bring the highest level of protection against certain types of impacts.