For this pattern you will need:

To fit chest 32/34 inches: 4 x 100g Balls.
To fit chest 34/36 inches: 5 x 100g Balls.
To fit chest 36/38 inches: 5 x 100g Balls.
To fit chest 38/40 inches: 6 x 100g Balls.

Needles needed: 4mm and 5mm.
1 Cable, 1Button.