You will need a circular needle size US 5 (3.75 mm) no longer than 16” (40 cm)

You will also need 5 buttons, approximately 3/4-7/8” (20 mm), Rowan used imitation horn buttons # TGB4775 Textile Garden

Finished measurements:
Chest circumference: 40.5( 44.5, 48.5, 52.25, 56.25, 60.25, 64.25, 68, 72)“ 103( 113, 123, 133, 143, 153, 163, 173, 183) cm
Finished length: 25.5( 26.5, 27.25, 28, 28.75, 29.5, 30, 30.75, 31)” 65( 67, 69, 71, 73, 75, 76, 78, 79) cm
Sleeve seam: 19” (48.5 cm) for all sizes