These 100% TIG welded tanks are hand fabricated one by one and hand fit to the U.S. Choppers boardtrack racer frame. They guarantee no imperfections and perfect alignment with every tank, or your money back. Each tank is comprised of a gas side and oil side. Contact with the cooler gas bladder along with only 3 quarts of oil, aid in cooling the oil and improving performance. Tank sets include both gas and oil cap as well as a petcock.