Premium leather main chassis constructed from 1.3 mm genuine bovine leather, Accordion leather stretch zones above the knee offer improved flexibility, Extended high rear waist construction provides greater overlap with the riding jacket, Large stretch panels on calf area for improved fit and feel, Pre-curved leg construction helps prevent riding fatigue and aids performance fit, Waist circumference adjustment, Waist connection zipper allows attachment to Alpinestars riding jackets, Internal mesh lining with stretch panel inserts work in conjunction with outer stretch zones for freedom of movement, Internally reinforced seat and knee area, Alpinestars GP-R protection on knee, Replaceable Sport knee sliders for excellent impact and abrasion resistance, Dynamic Friction Shield (DFS) external dual density Thermoplastic Polyurethane (TPU) sliders on knees