Size is as-packaged, or the diameter of loose marbles. ("D" is the diameter of round items other than marbles.)
Soft flannel-like mat measures 28" x 28" square (6x16x1.5" as packaged). Machine washable, non-toxic and fire retardant. Made in the USA. Includes 16 marbles with 2 shooters. A brief history, shooting techniques and rules for 3 marble games are included.