The Fox Baseframe Pro SL is a lightweight base layer chest guard with added D30 protection for the best of both worlds. The Baseframe is a lightweight layer that moves with your body so that you're not restricted. The D30 protection offers world leading impact protection that flexes and moves with your body as body heat will help the polymer to conform with your movements. The finishing touch is the built in hip padding for additional comfort. The Fox Baseframe Pro SL is a sleek and simple way to add another layer of protection for your rides. Features EN1621-1 Level 1 Back including high and low temperature conditions CE Certified D3O back plate features world leading impact protection technology Large perforation and flex grooves in the back foam contours and flexes with rider movement Body heat activates (softens) the polymer to conform to body Moisture wicking" open stretch mesh for breathability Built in padding at hips offers additional comfort D3O Viper back insert is removable for easy washing. Size Chart