Package includes: You will receive 40 expansion screws in 4 sizes, 10 pcs M4, 10 pcs M5, 10 pcs M6 and 10 pcs M8. The different specifications can meet your various use needs. Quality material: The jack nut is made of high-quality carbon steel material with electroplated zinc finish, anti-rust and -, high hardness and difficult to deform and break, for long-term use. Precise product detail: This metal crown nut has precise dimensions and threads and can fit the hole and bolt perfectly. Easy to install: These crown-shaped metal nuts are easy to install. Just insert the jack nut into the hole, then use a professional riveting tool to clamp the rivet nut and hold the screw and material in place. Wide application: These crown nuts are suitable for various types of base materials, such as iron plate, hollow plate, aluminum alloy frame, wallpaper board, wall cabinet, wall panels, clothes hangers, cardboard, thin plastic, license plate, drying rack and container label, . Color: Silver Material: Carbon steel Package contents: 1 set x petal rivet nuts Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture to be a little different from the real thing. The allowed measurement error is +/- 1-3 cm.