Chrome Molybdenum Alloy Steel for exceptional strength and long lasting durability. High visibility laser etched markings with additional hard stamping on the opposite side. Surface drive technology. Pin hole available for use with pin and o-ring for secure socket retention. Sockets come packaged in a reinforced molded case with sizes marked for quick identification and storage Case has reinforced steel hinges and buckles for added durability, security and strength. Set includes: Standard SAE sizes: 3/16" - 9/16"; standard Metric sizes: 4mm-15mm; Deep SAE sizes: 3/16" - 9/16"; Deep Metric sizes: 4mm-15mm; Universal SAE sizes: 1/4" - 9/16"; Universal Metric sizes: 5mm - 15mm; 2", 4" and 6" extensions, 1/4" Universal Joint and 1/4" F x 3/8" M Adapter.