A pattern for a cardigan in Sirdar Just Bamboo. Needles: 5.5mm (UK5, US9) and a 5.5mm 80cm circular if required. Number of 50g balls of Just Bamboo: Chest size 32 inches: 8 balls Chest size 34 inches: 9 balls Chest size 36 to 38 inches: 10 balls Chest size 40 inches: 11 balls Chest size 42 inches: 12 balls