Tech mesh and stretch mesh chassis construction for the optimum blend of light weight, breathability, flexibility and durability, Tech mesh and stretch mesh wide panels for enhanced airflow, Very large front hand pockets and a lower back compartment to store removable sleeves for real-world practicality, Waterproof inner compartment for secure and safe storage of essentials, Nucleon Flex Pro Shoulder and Elbow Protectors deliver optimum flexibility and airflow without compromising safety, Tech-Air? Ready, Protection upgrades (not included) Chest (full, NOT divided), Level 1: Nucleon Plasma Racing Chest Protector hook-and-loop/Nucleon KR-1 CELLI. Level 2: Nucleon Plasma Back Insert/Nucleon Plasma Long Back Insert/Nucleon Flex PROi Full Back Protector Insert/ Nucleon KR-2i.