Product Description: Color: Black, Quantity: 100/50/30/10/5, Material: Plastic, Head Diameter (max.): 20mm, Fit Hole Size: 8mm, Stem Length: 14mm. Rivet post pressure expands legs for fast and permanent fastening. Used widely for car fender, bumper, door or other car surface. These rivets are made of plastic material, fit 8mm diameter hole.