Charles is a generous scarf in 1/1 ribs with selvedge.

It’s one size only and it’s supposed to be as long as ten balls of yarn go.

You work it with the pair of 4 mm needles of your choice. That’s one size smaller than what you’d need to obtain a gauge of 17 stitches by 24 rows for a square of 10 by 10 cm in stockinette stitch.