A lightweight and flexible back protector that fits easily under outerwear is the Nucleon KR-Cell protector from Alpinestars. It offers excellent protection thanks to its innovative protective panels, which feature an ergonomic design that follows the contours of the motorcyclist's back.

Are you looking for a lightweight and adaptable back protector that provides a high level of safety and comfort? Then the Nucleon KR-Cell back protector is just what you need.

It features a new, single-phase injected grid shell structure with an ergonomic design that absorbs impacts. The cushioning of hard blows allows for maximum breathability and air circulation. Soft bio-foam padding is channeled throughout the protector for maximum comfort and fit. The new structured back shell is made from a high-performance polymer composite material for optimized flexibility and excellent weight-saving properties.

The integrated kidney belt with a double Velcro system keeps the protector close to the motorcyclist's body. Elastic, adjustable, and removable shoulder straps with a snap-fit system provide more comfortable use of the protector. Horizontal bending channels allow for an adaptable fit in various riding positions. The ergonomic design of the protector plates follows the natural contours of the back, ensuring an optimal fit while riding. The protector is highly perforated to ensure maximum breathability and ventilation.