The Impact Gold 9-pc 3/8" Drive 6-Point Impact Socket Set is machined from heat-treated alloy steel for extreme torque applications, including fastening applications by contractors and automotive technicians, with a black oxide finish for longer socket life. The 9-pc set includes a 1/4" Hex Shank Adapter with an Impact Gold 3/8” Square Drive Socket Adapter, which is machined from high-quality steel engineered for use with impact drivers, and tilts up to 15 degrees for work in tight areas.This set includes sizes: 5/16", 3/8”, 7/16”, 1/2”, 9/16”, 5/8”, 11/16” and 3/4”.