Size: The black dome bolt nut has a total of 145, including 50 pieces for M4, 30 pieces for M5, 20 pieces for M6, 20 pieces for M10, 15 pieces for M12 and 10 pieces for M8. Please carefully confirm whether the size is what you need before purchasing. Reasonable Design: The screw cap of the bolt covers is a round head design, which can prevent accidental damage caused by the nut and the screw protrusion. Protect your family and children from being scratched by the screws. Multi-function: The nut cover can prevent screws and nuts from rusting; Reduce dust pollution and extend the service life of screws and nuts; Avoid scratches and injuries. Material: The dome bolt covers and plastic storage box are made of high-quality plastic. It has no pollution, has good low temperature resistance, and will not be easily deformed and broken after long-term use. Easy to store: The plastic hex nut cover is placed in the plastic storage box according to the size, you can easily find the size you need. It can also be placed neatly after use. Easy to store, store and carry. Product Description Specification: - Name: Screw Bolt Cover Cap - Material: Plastic - Quality: 145Pcs - Weight: 210g - Color: Black - Size: M4, M5, M6, M8, M10, M12 Product Features: 1. Insulate the nut from the air, reduce dust pollution and rain washing, and slow down the rusting time of the nut; 2. Prevent the screw from aging and cracking in strong sunlight; 3. Add a delicate appearance to nuts and bolts; 4. Prevent accidental injuries; 5. Extend the service life of screws. Application: Mechanical equipment, valve, gas pipeline, bridge base guardrail, railway tracks, etc. Package includes: M4#: 50pcs Dome Bolt Covers M5#: 30pcs Dome Bolt Covers M6#: 20pcs Dome Bolt Covers M8#: 10pcs Dome Bolt Covers M10#: 20pcs Dome Bolt Covers M12#: 15pcs Dome Bolt Covers