"Marble Molds that are out of this world". Mike Close signed marble mold.

If you want to make marbles, this is the mold for you.The mold measures 5-1/8" square and 1-1/4" tall.
The six different sized cavities measure:  1/2" (13 mm),   3/4" (19 mm),   1" (25 mm),  1-1/4" (31 mm),  1-1/2" (38 mm), and 1-3/4" (44 mm).  
The rounded lip on each hole allows for a large variety of marble sizes up to 2 3/4 (69 mm) to 3 inches (76 mm).