This pattern is for adult sized barefoot sandals. It is crocheted with size 10 thread, or you can replace that with embroidery floss or other equal weight thread.
Gauge is not necessary for this pattern, but if you find your sandal to be too small or too large, adjust your hook accordingly.
This pattern looks great in a single color, or you can use many different colors to make it your own. The photo tutorial shows three different colors for ease of understanding the attachments, but feel free to work it in whatever color scheme you choose.