The ball shall be spherical; the outer casing shall be of leather or other approved materials. No material shall be used in its construction which might prove dangerous to the players.

The circumference of the ball shall not be more than 28 inches and not less than 27 inches. The weight of the ball at the start of the game shall not be more than 16 ounces nor less than 14 ounces. The pressure shall be equal to 0.6 - 1.1 atmosphere (==600 - 1,100 gr/cm(sq)) at sea level. The ball shall not be changed during the game unless authorized by the referee.

Decisions of the International F.A. Board

1. The ball used in any match shall be considered the property of the Association or Club on whose ground the match is played, and at the close of play it must be returned to the referee.
2. The International Board, from time to time, shall decide what constitutes approved materials. Any approved material shall be certified as such by the International Board.
3. The Board has approved these equivalents of the weights specified in the Law: 14 to 16 ounces = 396 to 453 grams.
4. If the ball bursts or becomes deflated during the course of a match, the game shall be stopped and restarted by dropping the new ball at the place where the first ball became defective, unless it was within the goal-area at that time, in which case it shall be dropped on that part of the goal-area line which runs parallel to the goal-line, at the point nearest to where the ball was when play was stopped.
5. If this happens during a stoppage of the game (place-kick, goal-kick, corner-kick, free-kick, PK or throw-in), the game shall be restarted accordingly.