GEARWRENCH® offers a wide range of impact sockets in open stock and sets that are designed to deliver the performance and strength that the professional users require. They are made from chrome molybdenum alloy steel for exceptional strength and durability. Sockets have a manganese phosphate coating to resist corrosion. The sockets also feature highly visible laser etched markings and a secondary size hard stamping. The sockets feature off-corner loading to reduce fastener rounding. The GEARWRENCH® impact product family will allow the professional user to forge ahead. GEARWRENCH® Socket Extension Set, Yes Impact Rated, Measurement System: Imperial, 4 Piece, 1/2 in Drive, Alloy Steel, Manganese Phosphate