Durability: AOBEN socket set made from Hardened Treated Chrome Vanadium Steel Alloy (Cr-V), can withstand extreme levels of torque changes against fasteners. Corrosion-Resistant: Manganese phosphate coating can improve wear resistance and corrosion resistance,can effectively extend the service life of the socket. Laser Marking: High-contrast size marking is permanently laser etched and easy to read, even in low light. SAE: 3/8", 7/16", 1/2", 9/16", 5/8", 11/16", 3/4", 13/16", 7/8", 15/16", 1". Totally 11 Pieces. Metric: 10mm, 11mm, 12mm, 13mm, 14mm, 15mm, 16mm, 17mm, 18mm, 19mm, 20mm, 21mm, 22mm, 23mm, 24mm. Totally 15 Pieces. Extension bars:3", 5", 10" Service Guarantee: AOBEN socket meet ANSI performance standards. It comes with 1 year quality guarantee.