With a flattering low profile design the r20 avoids the trap of sitting on top of your head and instead fits naturally around it the ergonomic dial gives you the precise custom fit you need for all day comfort when it comes to helmets comfort is also about protection in mold construction allows the hardened polycarbonate shell to be fused to the shock absorbing eps foam liner by combining these two layers during the construction process this keeps the weight down and allows for 21 vents