The extremely lightweight Level 2 CE and UKCA certified Nucleon Flex Proi Full Back Protector Insert features a highly ventilated hybrid of NucleonCell and Nucleon Flex protectors for the optimum balance of force dispersion and flexibility, with a soft-touch 3D mesh liner for enhanced rider comfort. The back protector insert is a full-length back protector, about 22% longer than regular back protector inserts. The Nucleon Flex Proi is compatiblewith all Alpinestars' sport and touring jackets that have released since Spring 2022, as all jackets have a double pocket to insert either a regular orlonger back protector insert. Features: Back Protector: EN 1621-2:2014 Level 2 (T+ & T-). The super lightweight back protector insert is developed in three waist-to-shoulder dimensions in order to cover all body sizes. High performance polymeric material Cell and Nucleon Flex structures for optimized flexibility and excellent weight saving properties. The back protector's design changes from the center towards the outside providing the perfect balance between energy absorption and flexibility. Soft comfortable 3D mesh on the body side of the protector offers breathability and rider comfort. Snap button compatibility for quick and easy use with Alpinestars suits and jackets. Rigorously tested and certified to for proven performance in extreme temperatures.