Alpinestars Nucleon KR-Cell Back ProtectorKeys, wallet, Cell. Extreme everyday protection for the street, the Alpinestars Nucleon KR-Cell Back Protector will become an indispensable part of your kit. And with its extremely low weight and high performance, it is so comfortable you will want to wear it every time you ride.Features: 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 formaximum breathability and air flow Single injected compound shell constructed with triple layer design to absorb impacts Soft bio foam padded chassis for maximum comfort Ergonomic protection plate contours to the natural curve of the back Horizontal flex grooves for adaptive fit in all riding positions Kidney belt for added position stability and security Adjustable, detachable elastic shoulder straps Compatible with the Alpinestars Nucleon KR-C Chest Protectors (sold separately) Compatible with the Alpinestars Nucleon KR-TB Protector (sold separately) CE certified to EN 1621-2:2014 Level 1