The collagen fibers are those proteins that give our cartilage its strength, and the elastin fibers of those proteins that give the cartilage its flexibility. So we have three types of cartilage connective tissues. We have the highland cartilage, we have the elastic cartilage, and we have our fiber cartilage. And these different types of cartilage differs from one another based on the concentration of these substances inside the matrix of that particular cartilage. So let's begin with the highland cartilage. So the highland cartilage is basically a transparent type of cartilage, so we can see through that cartilage.