This is an ingenious idea. You can get a perfectly matching pair of socks out of one of these 100g balls. There are two markers of a length of yellow yarn, start knitting after the yellow yarn for the beginning of each sock and the pattern will come out the same each time. It's the same wonderful, hard-wearing Regia sock yarn, the ball band shows how the socks will come out. Ideal for those of us whose eye starts to twitch at 'fraternal' socks! Most of these designs have been done by Scandinavian knitting duo, Arne & Carlos. The Arne & Carlos designs are more complex fair isle socks.