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b. The ball shall conform to one of the types specified in the table immediately below or in the table under paragraph (d). 

<img src='content_image/714876.jpg'>

Notes: 

1 This ball type may be pressurised or pressureless. The pressureless ball shall have an internal pressure that is no greater than 7kPa (1 psi) and may be used for high altitude play above 1,219 m (4,000 feet) above sea level and shall have been acclimatised for 60 days or more at the altitude of the specific tournament. 

2 This ball type is also recommended for high altitude play on any court surface type above 1,219 m (4,000 feet) above sea level. 

3 This ball type is pressurised and is specified for high altitude play above 1,219 m (4,000 feet) above sea level only. 

4 The deformation shall be the average of a single reading along each of three perpendicular axes. No two individual readings shall differ by more than 0.08 cm (0.031 inches). 

c. In addition, all ball types specified under paragraph (b) shall conform to the requirements for durability as shown in the following table: 

<img src='content_image/714883.jpg'>

