340 pieces inner tooth Starlock lock washers clamping washers M3-M12 assortment Features: 100% brand new and high quality. Organized for case, easy to store and use. Made of high quality 65 manganese steel, hard and durable. The package contains 7 M3 M4 M5 M6 M8 M10 M12 sizes (280 pieces in total) in a transparent box suitable for different sizes of fasteners. A lock washer exerts a spring force between the head of the fasteners and the substrate to create more friction and rotational resistance. Perfect accessory for shock absorption and isolation for machinery equipment. Specification: Material: 65Mn metal steel Size and length: M3: 9 mm M4: 12 mm M5: 12 mm M6: 14 mm M8: 18 mm M10: 20 mm M12: 25 mm Box size: Approx. 17.5 * 9.8 * 2.2 cm / 6.9 * 3.8 * 0.86 inches Weight: 193 g Application: Perfect accessory for shock absorption and insulation of machine systems Delivery content: 60 pieces M3 washers 60 pieces M4 washers 60 pieces M5 washers 50 M6 washers 50 M8 washers 40 M10 washers 20 pieces M12 washers