31592 is a 24 piece, 3/8inch insulated socket drive set (metric). It is individually tested to 10,000VAC and rated to 1,000VAC (1,500VDC) for safety and peace of mind in energized applications. It is VDE Certified and meet EN/IEC 60900 testing standards for protection against arc flash explosion, ASTM F1505 standard specifications for insulated and insulating hand tools, NFPA-70E standards for electrical safety on the jobsite, and CSA testing benchmarks for safety and performance. The Metric insulated socket set comes with an assortment of sockets for a range of fastener sizes. Sockets come in sizes that are measured in millimeters to fit fasteners with a metric size head.