【High Quality Material】High quality 304 stainless steel provides strength and good corrosion resistance in many environments.【Environmental friendly】Screws are made of high quality stainless steel, and the storage box is made of non-toxic plastic. Not only because it is made from premium quality elements, but also mercury-free and toxic-free. that you can classify the screws in an organized way, which can make these hex screws more convenient to carry and remove. desktop, furniture and other machinery, if you need, this set of hex socket screws will be an ideal choice for you.【Basic Information】Sizes: M3 M4 M5. Length: 10mm, 12mm, 16mm, 25mm. Material: 304 Stainless Steel Screw Type: Hex Head Screws