This product is made of fine quality stainless steel material not easy to rust clear lines.Features:Made of fine quality stainless steel material not easy to rust long-lasting to use.Deep thread even tooth path.Smooth surface no burrs clear lines without skid.High hardness and corrosion resistance.Stainless steel material will not release toxic substances non-toxic environmental protection.Specifications:Item type: NutMaterial: 304 Stainless SteelSelection type: M-3 M4 M6 M-8 M10 M12(optional)Quantity:Package weight: M-3: 4g/0.14ounces M-4: 6.5g/0.22ounces M5: 8g/0.28ounces M6: 21.5g/0.75ounces M-8: 42g/1.48ounces M-10: 94.5g/3.33ounces M12: 131g/4.62ouncesPackage size: 120*80*20mm/4.72*3.14*0.78inchesPackage list:5PCS*Nuts