Bingo balls must be:

(1) A set of seventy-five balls bearing the numbers one through seventy-five and the letters B, I, N, G, or O, though the letters B, I, N, G, O need not appear if the operator is playing three number speed or hidden face bingo games; and

(2) Available for inspection by the players before a bingo session begins to determine that all are present; and

(3) The same weight as each of the other balls and free from any defects; and

(4) Distinguishable from all other sets of balls in play.