Collagen types are a biological classification. Type I collagen is found in bones and skin. It accounts for more than 90% of organic mass of bone and is also the major component of skin, tendons and ligaments. Type II collagen is the main collagen of cartilage, and is mainly presented in combination with proteoglycans including chondroitin sulfate. It is therefore a different product, to find out more information on type II collagen visit the Peptan IIm site.