Yarn requirements:

Outer mitten: 2 oz (56.5 g) dark worsted-weight wool, 2 oz (56.5 g) light worsted-weight wool

Inner mitten: 2 oz (56.5 g) sport-weight wool

From the description: Lined mittens are basically two mittens that are joined together at the cuff - a lightweight inner mitten tucked inside a heavyweight outer mitten. They are very snug and warm.