【Durable for long term use】- High quality 304 stainless steel provides strength and good corrosion resistance in many environments. 【Bearing surface】- Have enough bearing surface that can be screwed more tightly. 【Transparent 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 clear storage case for quick access and protection. 【Use】Widely used in household and office appliances, communication equipment, ship assembly and other machinery industries, furniture, car and motorcycle repair and DIY inventions! Can also be used for storage box fastener components, industrial and construction fasteners. Ideal for use in confined spaces where the head needs to be flush or below the surface. 【Basic hardware information】- Material: 304 stainless steel / Drive type: hex socket / Head style: round head / Size: different size from M3 M4 M5 (include M3 M4 M5 nuts)