5 buttons needed.

Sizes available:
81, 86, 91, 97, 102, 107, 112 cm. (32, 34, 36, 38, 40, 42, 44 in.)

Length of back from top of shoulders:
46, 47, 48, 52, 53, 54, 56 cm. (18, 18.5, 19, 20.5, 21, 21.5, 22 in.)

20g balls needed:
7, 8, 9, 10, 11, 12, 13