Socket set includes: This adapter set includes 3 pieces. Reducers and 3 pieces. Adapters: 3/8" (F) to 1/4" Drive (M) reducer, 1/2" Drive (F) to 3/8" Drive (M) reducer, 1/4" Drive (F) to 3 adapter /8" Drive (M), 3/8" Drive (F) to 1/2" Drive (M) adapter High quality socket set: these adapters and reducers are made of chrome vanadium steel high strength, heat treated and have a corrosion resistant nickel/chrome finish for industrial, mechanical or construction work -High quality socket set: these adapters and reducers are made of chrome steel high strength vanadium, heat treated and have a corrosion resistant nickel/chrome finish for industrial, mechanical or construction work. These adapters meet and exceed ANSI/ASME standards. p> -Easy to store: All parts are well packed and assorted in a plastic box for easy storage and transport. It can also simplify repair work 1 x 6.3 mm (1/4") inner square adapter - 10 mm (3/8") outer square, load max. 60 Nm 1 x inner square adapter 10 mm (3/8") - outer square 6.3 mm (1/4"), max. 60 Nm 1 x inner square adapter 10 mm (3/8") - outer square 12.5 mm (1/2"), max. 200 Nm 1 x inner square adapter 12.5 mm (1/2") - outer square 10 mm (3/8"), max. 200 Nm 1 x inner square adapter 12.5 mm (1/2") - outer square 20 mm (3/4"), max. 500 Nm 1 x inner square adapter 20 mm (3/4") - outer square 12.5 mm (1/2"), max. 500Nm