Rule 2    The Ball
Section 1
BALL DIMENSIONS
The Ball must be a “Wilson,” hand selected, bearing the signature of the Commissioner of the League, Roger Goodell.
The ball shall be made up of an inflated (12 1/2 to 13 1/2 pounds) urethane bladder                 enclosed in a pebble grained, leather case (natural tan color) without corrugations of any     kind. It shall have the form of a prolate spheroid and the size and weight shall be: long     axis, 11 to 11 1/4 inches; long circumference, 28 to 28 1/2 inches; short circumference,     21 to 21 1/4 inches; weight, 14 to 15 ounces.
The Referee shall be the sole judge as to whether all balls offered for play comply with             these specifications. A pump is to be furnished by the home club, and the balls shall             remain under the supervision of the Referee until they are delivered to the ball attendant     just prior to the start of the game.
Section 2
BALL SUPPLY
Each team will make 12 primary balls available for testing by the Referee two hours and 15     minutes prior to the starting time of the game to meet League requirements. The home     team will also make 12 backup balls available for testing in all stadiums. In addition, the     visitors, at their discretion, may bring 12 backup balls to be tested by the Referee for         games held in outdoor stadiums. For all games, eight new footballs, sealed in a special         box and shipped by the manufacturer to the Referee, will be opened in the officials’             locker room two hours and 15 minutes prior to the starting time of the game. These balls     are to be specially marked by the Referee and used exclusively for the kicking game.
In the event a home team ball does not conform to specifications, or its supply is                     exhausted, the Referee shall secure a proper ball from the visitors and, failing that, use     the best available ball. Any such circumstances must be reported to the Commissioner.
In case of rain or a wet, muddy, or slippery field, a playable ball shall be used at the             request of the offensive team’s center. The Game Clock shall not stop for such action (unless undue delay occurs).
Note: It is the responsibility of the home team to furnish playable balls at all times by             attendants from either side of the playing field.