Complex sentence: DC Shoes is an American company that specializes in footwear for extreme sports, skateboarding, snowboarding as well as snowboards, shirts, jeans, hats, and jackets.
Split into simpler sentences: DC Shoes is an American company that specializes in footwear for action sports, including skateboarding, snowboarding, and snowboards. The company also manufactures shirts, jeans, hats, and jackets.