Precise Forging process leads to a stiff chain for better acceleration and more efficient engine work Lightening hole allows for a lighter chain without compromising strength while removing mud and dispersing heat more efficiently Improvement in transmission efficiency Special pin with holes in both ends allow the chain to be lightened Edge-cut inner plate reduces friction and allows for smooth engagement with sprocket Chromium Carbide pin surface coating increases hardness and reduces chain wear. CHAIN 3D 520GP X 120 GLD