Poc joint vpd system kneepocs joint vpd system knee is a 2 ply highly flexible knee protector it features a highly efficient ventilation system for optimum moisture management and comfort the outer fabric is made of high tenacity polyamide yarns to ensure low friction and high abrasion resistance vpd is the ideal material for mtb as it wraps around the body shape when warm giving greater freedom of movement on the bike upon impact the vpd technology hardens to minimise injury featureslo