Quality Materials: These adapters and reducers are made of high strength 45# steel, heat treated and have a chrome plated finish which is corrosion resistant, rustproof, high hardness, wear resistant, sturdy and durable. Design Tips: The spring loaded distraction balls of the adapters lock the sockets securely, get the most out of your sockets with this handy set of adapters and reducers that ensure you always have the right size for the job. Usage: Fits comfortably and securely into your drill chuck or hand held driver. Consisting of your most common bit sizes 1/4", 3/8", 1/2" and 1/3" change shank sizes Provides versatility and convenience no matter what tool you have chosen to use. Set Includes: This adapter set includes 6 pieces. 8pcs Reducers. Adapters: 1/4" - 3/8" adapter, 3/8"- 1/4", 3/8" - 1/2", 1/2" - 3/8", 1/4" - 1/2", 1/2" - 1/4" Drive (M). Reducer: 1/4" reducer (25, 30, 50, 65mm), 3/8" reducer (50, 65mm), 1/2" reducer (50, 73mm). Wide Application: Hexagonal conection shank