Answer:
All balls must be:
spherical.
made of suitable material.
of a circumference of between 68 cm (27 ins) and 70 cm (28 ins)
between 410 g (14 oz) and 450 g (16 oz) in weight at the start of the match.
of a pressure equal to 0.6 – 1.1 atmosphere (600 – 1,100g/cm2) at sea level (8.5 lbs/sq in – 15.6 lbs/sq in)
unless you were talking about something else, this is my current answer for you