Thin Brass Ball Marker - "Black Hole" / "Cubes #2"

Thin and light brass ball marker with milled op-art patterns on both sides.  "Black Hole" design on one side; "Cubes #2" design on reverse. Just under 1.3" in diameter and the same thickness as a quarter.   Weight is approximately 7g.   (For comparison purposes, a quarter weighs about 5.7g and is about 0.96" in diameter.)