This is a section of Aristo-Craft 30122 USA Style Brass 12.5 Foot Diameter Curved Track. Aristo-Craft track is widely known for its outstanding quality, long-lasting durability, and most of all, affordability. Instead of being hollow, the rail in Aristo-Craft track is solid for strength and performance. Aristo-Craft's brass rail has a very high percentage of copper insuring that conductivity of Aristo-Craft track is superlative. This brass rail also features a very low percentage of lead, greatly inhibiting oxidation. The Aristo-Craft Screw/Rail Joiner System is a pride of Aristo-Craft design. It provides terrific conductivity where normally conductivity is a problem? the junction. This means there is no need for messy conductive greases, soldering between joints, or rail clamps to get electrical performance.