Alpinestars Leather Track Pants Sport riding pants suitable for track and street use. 1.3 mm full-grain leather. Perforated leather panel inserts. Accordion leather stretch zones improve flexibility. Extended rear waist construction. Ergonomically placed stretch Kevlar panels. Patented calf expansion pockets improve range of fit. Multiple-stitched main seam construction for maximum tear resistance. Inner mesh lining with stretch panel inserts work with outer stretch zones for a snug fit. Internally reinforced seat area. Removable CE certified GP protectors. Foam padding built into the hip area. Internal waist connection zipper for attaching to riding jackets. Alpinestars replaceable Sport knee sliders. YKK Semi Auto Lock zippers.