Premium plastic: With high-quality PE plastics, durable, difficult to deform. The plastic hex nut cover is corrosion resistant, does not age, prevents ultraviolet rays with good low temperature resistance, light weight, good toughness and protects nuts and bolts. Protective screws: these rubber hex nuts can protect the screws from rust, water, dust, etc., reduce dust pollution and rain, prevent screw corrosion, beautify the appearance, extending the service life of the screw. Many sizes: 145 sets, M4 x 50, M5 x 30, M6 x 20, M810, M10 x 20, M12 x 15. Black, the quantity is enough for your daily use for hexagonal bolts and nuts to improve the life of nuts and bolts, easy to install and disassemble. With a stored box: with a transparent plastic box, it is easy to store and carry, clear, easy to find. When you use it, you can find a suitable nut cap, you can quickly find the appropriate nut cover, save time. Wide range of applications: suitable for machine equipment, petrochemical, valve, gas pipeline, bridge base guardrail, street lights and other places. Provide external nuts and screws to prevent weathering and damage.