Thin sheets of metal, plastic, or other materials can be clamped together from one side, by means of blind rivets, better known as pop rivets. A tubular rivet is inserted in a hole which is drilled onto two sheets. It is then clinched by withdrawing a nail found inside the rivet. These fasteners are installed with a manual, pneumatic or electric rivet gun, to connect metal and other pieces together. The general public is under the impression that all pop rivets have aluminium heads, and would therefore not know where to find pop rivets having a head made out of other metals, such as copper. These rivets have copper heads. They are mostly found in jobs where copper sheeting is used. Since some metals are not compatible with each other, copper rivets are sometimes used as a substitute, when they are considered to be more suitable.