The back protector insert is a full-length back protector, about 22% longer than regular back protector inserts. The Nucleon Flex Proi is compatible with all Alpinestars’ sport and touring jackets that have 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 Proi is to deliver full-length coverage in terms of protection like a fixed back protector does, but with the practicality of an insert. 1. In terms of construction, the hybrid technology blends the best properties of Cell and Flex technologies to create an ultra-protective solution that delivers premium, breathable performance, and maximum flexibility.

2. The protector has an ergonomically contoured dual zone outer shell constructed from an advanced polymeric blend with a solid Cell structure core framed by a more
flexible 3D Cell structure as the first line of defense; this is reinforced even further with the Nucleon Flex technology layer on the central back zone.

3. The protector is backed with a breathable soft-touch 3D mesh liner for maximum airflow and optimum rider comfort. Nucleon Flex Proi Full Back Protector Insert