The rivet consists of two parts. The head of the rivet has a diameter of 7 mm.
The pin is about 2.7 mm in diameter. This means that you have to punch a hole with a diameter of at least 2.7 mm in the leather. The pin is about 6 mm long, which means that you can join leather parts with a total height of 6 mm and less. Both parts of the rivet are put together and pressed together with pliers or a hammer.