This is a one circular needle, cuff down pattern, originally designed for Felici self-striping yarn as an alternative to “plain” stripes.

There are two heels included, a short row heel and a rounded heel with heel flap. There are also two charts for “right” and “left” socks. The short row heel is recommended for self-striping yarns because it keeps the width of the stripes at the heel and continues the striping pattern on the sole of the foot.