Features: 100% brand new and high quality. Spring washers can prevent nut from automatic loosening, mainly used for occasions with vibration load or alternating load, tighten to prevent loosening. Made of high quality stainless steel material, these washers are wear-resistant and corrosion-resistant. 10 specifications are available: M3, M4, M5, M6, M8, M10, M12, M14, M16, M20, each of type has different quantities. Suitable for electrical connections of domestic and commercial appliances, automotive and marine applications. Specification: Material: Stainless Steel Weight: Approx.17g~54g / 0.6oz~1.9oz Type: 100pcs*M3, 100pcs*M4, 100pcs*M5, 50pcs*M6, 50pcs*M8, 20pcs*M10, 10pcs*M12, 10pcs*M14, 10pcs*M16, 5pcs*M20 (Optional) Package List: 1 set * Wave Washers Note: Please allow slight error due to manual measurement. Thanks for your understanding.