Qualities and measurements

The ball is:

• Spherical
• Made of leather or other suitable material
• Of a circumference of not more than 70 cm (28 ins) and not less than 68 cm (27 ins)
• Of a pressure equal to 0.6 – 1.1 atmosphere (600 – 1,100 g/cm2) at sea level (8.5 lbs/sq in – 15.6 lbs/sq in)