the circumference of a soccer ball must not be more than 28 inches (70 centimeters) and not less than 27 ins (68 cm)
the soccer ball used in professional leagues and in the FIFA WORLD cup is called "size 5"
it is spherical and made of leather or some other suitable material
it must not weigh more than 16 ounces (450 grams ) and not less than 14 oz (410 grams) at the start of A match
the ball must be of a pressure equal to 0.6-1.1 atmosphere (600-1000 g/cm2) at sea level (8.5 Ibs/sq in)