Yarn yardage approximate. Gauge measured “at rest” (unstretched).
Size given probably fits a woman’s foot of shoe size 8.5 to 9.5.

Slippers may be worked all in one color, or in a repeated stripe pattern of several colors.

The linked blog post provides more description about construction and seaming rationale!

The post gives three free PDF patterns for items employing double rib: these slippers, plus a bottom-up baby hat and a color-stripe cup cozy.