Alpinestars Nucleon Plasma   The extremely lightweight Nucleon Plasma back protector is made from a unique shock-absorbing material. The protector can be inserted quickly and comfortably for safe riding fun! The clever design focusses on adaptability, breathability and ventilation. With its soft-touch textile coating on the back, this protector offers an optimum balance between power transmission, flexibility and comfort. Suitable for Alpinestars jackets.   Comfort/features:   very light and flexible shock-absorbing material innovative design allows the protector to self-compress and expand ultra-adaptive fit for optimum riding comfort adapts perfectly to the body thanks to the soft-touch textile coating perforations promote air circulation inside the jacket (Air Cooling System) and offer extra comfort Side and longitudinal ventilation channels for effective heat dissipation Safety: tested according to EN 1621-2:2014, level 2 Material: 95% polyurethane foam, 5% polyester   Size: Size S = suitable for Alpinestars jackets: Women's size 36-40 / XS-S Size M = suitable for Alpinestars jackets: Women's size 42-50 / M-3XL, Men's size 44-50 / XS-M Size L = fits Alpinestars jackets: Men size 52-68 / L-6XL