Fixation yarn is a stretchy yarn made from Cotton and Elastic so it is great for folks who have allergies to wool or find wool to be scratchy. Fixation yarn is also popular for doing chemo hats for friends with cancer or donating to cancer hospice organizations around the country.98.3% Cotton / 1.7% SpandexWeight: 50 g / 1.75 ozApprox: 100 yds / 91.4 mKnitting Needle Size: US 5 - 9 / 3.75 - 5.5 mmKnitting Gauge: 22 sts = 4" (10 cm)Suggested Care: Machine Wash Warm. Lay Flat to Dry.