TorusA torus is a surface of revolution in geometry, resembling a doughnut or inner tube shape. It's formed by rotating a circle in 3D space around an axis that lies in the same plane as the circle, but does not intersect it. If the space inside the torus is also filled in, like this gorgeous centre knob, it's usually called a solid torus. At 150mm in diameter and shown here cast in solid bronze with a satin brushed finish, Torus is also available in brass