The PP shell is strong and anti falling. It adopts PP material new design shell. It accords with ergonomics and is comfortable. The inner lining is thickened and the 0.8cm is designed to be thickened. It has good cushioning resistance and thermal insulation. Double layer Velcro design for different groups of people, special double Velcro wears freely. size： Length: 30cm Width: 30cm Height: 30cm High protection shell 30cm Shell width 30cm Specification： Products: anti-collision, wind proof and kneecap. Size: uniform code (adjustable tape) 35cm 45cm Material: PP shell, EA foam. Weight: about 300 grams.