Assertion: ball | /r/HasProperty | air-filled sphere
Facets:
value: with a circumference of 68–70 cm
type: OTHER
Source sentences:
text: Law 2 of the game specifies that the ball is an air-filled sphere with a circumference of 68–70 cm (27–28 in), a weight of 410–450 g (14–16 oz), inflated to a pressure of 0.6 to 1.1 atmospheres (60–111 kPa or 8.7–16.1 psi) "at sea level", and covered in leather or "other suitable material".