This is the place to post questions and discussions on usage and style. The members of the Wordwizard Clubhouse will also often be able to help you to formulate that difficult letter.
They aren't circles. It is a coil of barbed wire.
I'm puzzled therefore I think.
The enlarged image seems to depict a more injurious form of barbed wire called razor wire, where the coils of wire are studded not with barbs but with blades.
tony h and Erik : Thank you two very very much for the terms. I really appreciate it.