These are a pair of biologically inspired hoops which resemble a section of a
DNA molecule. They are mirror images of one another, so the
double helix will go clockwise on one and counterclockwise on the other. The sizes are 75 mm (3") in diameter and the stems are 10 mm (0.4") long by 1.1 mm (0.04") in diameter.
There is another more curly version of these here: Double Helix 75 mm (3") Hoops - curly