From the manufacturer:
A unique metallic thread for all needle arts! A strong, smooth, kink-resistant metallic, it is comparable to a crochet cotton size 20. Each ball is 25 grams and approximately 25 yards. Steel crochet hooks size 9-10 (1.15-1.25mm) recommended. Tatting needle size 5-0 or 7-Fine recommended. Knitting needle 0000 (1.25mm) recommended. Because it is not made of a natural fiber like cotton, there can be a small variance in size from color to color. Care: Liz Metallic is handwashable in cool water or machine washable in cool water on the gentle cycle. Do not use bleach. It can be tumble dried on low setting. If ironing, do not iron directly on the thread, use a pressing cloth and do not use steam. The metallic thread is dyed so in the first washing it could bleed a little.