1. Heavy-duty chrome vanadium steel construction is designed for use with keys and wrenches. 2. Socket adapters are made of heavy duty chrome vanadium steel for durability and long life. 3. The surface of each adapter is finished by galvanizing and blackening, which ensures corrosion resistance. 4. The adapter body is designed with a spring loaded ball trigger and a small hole to keep your outlets stationary and secure. Get the most out of your outlets with this handy set of adapters and reducers that ensure you'll always have the right size for the job 5. There are four different size plug adapters and you can use for different plugs. Can meet your different needs. Note: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Sold by-Minnanxin