Battleship Gray Marbles 14mm Glass Marbles Pack of 20 Wondertrail WONGM028 Battleship Gray Marbels 14mm Glass Marbles Pack of 20 Useful as replacement marbles in games. Each blister contains 20 glass marbles. Glass marbles are 13-15mm Approximately 9/16 inch in size. NOTE: Colors may vary slightly depending on your monitor settings.