1.High quality steel material: High quality steel provides strength and offers good corrosion resistance in many environments. Good bearing capacity and high strength, resistance to rust and excellent resistance to oxidation in a bad environment such as high temperature, cold weather and in environments where there is humidity, ensure durable for long-term use.2.Drive Type: Hex Socket / Head Style: Button Head / Size: Various sizes of M2 M3 M4 (including M2 M3 M4 M5 nuts and washers). 1080pcs Mixed Screws And Nuts Set Meet Your Different Needs. It is a very important tool for the family.3.Stressed Surface: The nut and bolt sets come with standardized metric system. The wire is very clean without burrs, has enough stressed surface that can be screwed tightly.4.Clear case for quick access: All screws and nuts will be packed in a sturdy plastic box, this set is organized by size/type in a transparent storage case for quick access and protection.