High-end approved Alpinestars SuperTech R enduro-motocross boots, made of extensible microfiber accordion, to offer greater freedom of movement.Ref. 22200211100. High-end approved Alpinestars SuperTech R enduro-motocross boots. The biomechanical inner liner, in addition to being removable, provides excellent flexibility in the areas where it is most needed and rigidity in the most critical areas during a fall.