[What You Get] - You will get 10pcs copper rivets in 12mm x 4mm x 21mm/0.47" x 0.16" x 0.83"(OD*Pin Dia.*H) and 10pcs copper burrs in 12mm x 4mm x 0.9mm/0.47" x 0.16" x 0.035"(OD*ID*T). No more or less quantity, to satisfy your daily basic DIY or repair needs. [Material] - The solid rivet set is made of copper, which has corrosion resistance, wear resistance, long-lasting durability, and ductility feature and is not easy to break. The matching washers can make installation much tighter for ensuring long-lasting strength and support. [Fastening Function] - Copper rivets and burrs have a cylindrical shape with a head at one end and a tail at the other. The head sits on the surface of the material being fastened while the washer and tail are hammered down to fix the rivet in place to offer a sturdy and reliable fastening solution for a wide range of applications. [Easy Installation] - Simple to install hammer-in design. To create a firm hold, use a hammer to hammer the washer in place and cut off the extra pin length with a plier, and then use a tool that flatten or round the tail. Some rivets and burrs may also require a hole punch to create a hole in the material before installation. (Installation tools are not provided.) [Versatile Applications] - Use these rivets for crafting, repairing, or even decorating. They are perfect for leatherwork, handmade crafts, and many other applications, like making and repairing belts, bags, keychains, straps, purses, jeans, shoes, and other leather ornaments.