The entire inner edge lies above the entire outer edge as though it were formed over a spherical body. The cross section is a sophisticted semi-elliptical airfoil. The brass Chackrum really sails. I have thrown it, Frisbee style for more than 100 metres and it flies straight and true. The steel Chackra fly only 40 - 60 metres.
Outer edges are on right.
Examples of Chackrum Metal Throwing Rings from India The Snoopy Ruler is 12 inches in length. An enlargement of the four Chackrum surfaces is depicted below. The top two rings appear to be made out of stainless steel. A few decorative marks with circles and lines is easily seen. These marks are repeated in a regular pattern around their perimeter.