8 pieces, 1 1/2 X 3/4" the largest, Lovely striped 5/8" Diameter the smallest. Many shades and colors. One looks like a piece of coral. Smooth flat shells work as well as a flat rock to get the chi flowing along your spine. This is a technique my chiropractor taught me. Convo me if you would like to know how to do it. It is invigorating to the body and helps your back.