Alpinestars Nucleon KR-Cell Back Protector • 3 waist-to-shoulder dimensions in order to cover all body sizes. • Back shell plates constructed from a high performance polymeric material blend for optimized flexibility and excellent weight-saving properties. • Highly perforated shells for maximum breathability and air flow. • Single injected compound shell constructed with triple layer design to absorb impacts. Available in multiple sizes and/or colours — select your variant.