You will need a stitch holder and 5(5, 6, 6, 7, 8) buttons.
Sirdar used their button B5611-0485 for this design

Finished measurements:
Chest circumference: 19(21, 22.5, 22.75, 23.75, 24)“ 48(53, 57, 58, 60, 61) cm
Finished length: 10.25(11, 12, 13, 13.75, 14.5)” 26(28, 31, 33, 35, 37) cm
Sleeve length: 6.25(6.5, 7, 8, 8.75, 9.75)“ 16(17, 18, 20, 22, 25) cm

Yarn used:
Sirdar Snuggly Snowflake Chunky
A. Shade 209 Sleepy Time - 1 (1, 2, 2, 2, 2) balls

Sirdar Snuggly DK
B. 353 Indigo Mix - 1 ball for all sizes