Large, thick, flat disk, smooth black button hand-carved from water buffalo horn. Eight recessed lines / slashes are gray. Dynamic, strong but light. Shape, size, and color are pretty consistent button to button; the slashes vary a bit since they're done by hand one at a time by button artisans. India.Wonderful. 

Both sizes are approximately 3/16" thick. Pick your size, 1-1/2" or 2"