Tekton impact drive sockets have two size markings—both a high-visibility laser marking and a permanent stamped marking. The interior well of the socket extends fully into the socket, which allows for better fastener engagement in more situations. Each socket works with both friction ring and detent pin anvils. Smooth walls without grooves support friction ring engagement, and a detent pin hole on one side allows you to decide whether to engage the pin. Radiused corners on the socket prevent fastener round-off by applying force to a fastener's flat sides, rather than its corners. Part by part, we choose the best combination of steel alloys, heat treating specifications, and forming processes to meet the highest performance requirements. All pieces in this set have a corrosion-resistant manganese phosphate coating. This set includes a carrying case made of high-density polyethylene that withstands common lubricants, fuels, and solvents.