Features Made of premium material, these locknuts are sturdy and durable. These lock nuts are an amazing replacement for normal hardware nuts, vehicles, domestic or outdoor applications. They can prevent vibration from loosening a bolted joint, resist loosening under vibrations to provide a locking action. Locknut size is M 4, comes with 10 pieces in total. Simple and quick to use, convenient to tighten or loosen. Description: Material: Aluminium/Nylon Type: Aluminum Alloy Hex Nuts Surface Treatment: Anodized Size: M4 Colour: black. Quantity: 10pcs/bag Note: Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package includes: 1 x 10 Self-locking Nuts with Nylon Insert Package List