Durable for Long Term Use - High quality 304 stainless steel provides strength and good corrosion resistance in many environments. Stress Bearing Surface - Offers sufficient stress bearing surface which allows for tighter screwing. Clear Case for Quick Access - All screws and nuts are packed in a sturdy plastic box; the set is organized by size and type in a clear storage case for quick access and protection. Usage - Widely used in household and office appliances, communication equipment, ship assembly, machinery industries, furniture, car and motorcycle repair, and DIY projects. Suitable for use in confined areas where the head needs to be flush or below the surface. Material Basic Info - Material: 304 stainless steel / Drive type: Hex socket / Head style: Button head / Size: Various sizes from M3, M4, M5 (includes M3, M4, M5 nuts)