Cross, heart, pyramid, star...etc.
Decorative rivets, Bezel conchoes, Plastic stone rivets.
It is a rivet to use when stacking thick leather together.
Strike with a peening tool.
Use this when you want the intensity, such as attaching handles or shoulder straps.
Screw Back.
Copper Rivets are great for riveting leather items such as belts, wallets.