- Plastic hinged screw caps, ideal for protecting and decorating screws - Premium material: flame-retardant, oil-resistant, corrosion, acid and alkali resistant - Compatible with M3 and M4 screws, heads up to 8 mm in diameter and 3 mm thick - Includes 100 units (50 white and 50 black) for multiple applications - Easy installation: snap on and keep screws covered - Prevent oxidation and improve the appearance of furniture, walls, and surfaces - Recommended for use in home, office, garden, stores, and schools - Smooth surface makes cleaning easy and extends the screw's lifespan