The extremely lightweight Level 2 CE and UKCA-certified Nucleon Flex Pro Back Protector Insert features a highly ventilated hybrid of Nucleon Cell 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 Pro is compatible with all Alpinestars’ sport and touring jackets that have been released since Spring 2022, as all jackets have a double pocket to insert either a regular or longer back protector insert. The goal of the Nucleon Flex Pro is to deliver full-length coverage in terms of protection like a fixed back protector does but with the practicality of an insert.