Red Heart Bamboo Wool Yarn. This fabulous yarn is made of sustainable bamboo and features a wonderful hand and felts too! Weight category: 4; 55% Bamboo/45% Wool; 1.76oz/50g; 87yd/80m. Gauge: knit: 20st x 23r = 4in/10cm on size 8/5mm needles; crochet: 12sc x 15r = 4in/10cm on size I9/5.5mm hook. Care: Hand wash cold water; dry flat; do not bleach; do not iron; do not dry clean. Imported.