The STANLEY® 1/2 in. Drive 5/8 in. A/F Spark Plug Socket features a Maxi Drive profile with a unique radius corner design which provides 15% more toque, making it easy to tighten fasteners and simplifies the turning of rounded corners. Made of high alloy steel and heat treated for performance, the nickel chrome plating protects against corrosion, while the gripping helps reduce slipping on frozen or rusted fasteners. All sockets meet or exceed ANSI specifications.