"Impact sockets are forged from high-quality chrome molybdenum alloy steel for durability and superior strength. Patented sidewall drive sockets apply force to the walls of the fastener instead of the points, resulting in longer fastener life. Laser-etched, hi-visibility markings allow for easy readability. Meets or exceeds ANSI and government torque performance specifications. Drive in. 3/8, Material Type Chrome molybdenum, Measurement Type Standard SAE, Pieces qty. 8, SAE Deep Socket Size in. 5/16-3/4, Specialized Pieces qty. 0, Storage Type Plastic case, Point 6."