​The Sock Ruler® ​is constructed of a heavy duty, yet flexible plastic; an innovative measuring tool for sock knitters that goes inside of the sock, allowing it to lie flat and ensure accurate measurements (both metric and imperial).

The Sock Ruler: is for adult sized feet and children size large
The Sock Ruler Junior: is a set of two, one for babies and one for infants
The Sock Ruler Combination: includes all three Sock Rulers!

Easy to use, no tape measure blues! ....and made in the USA!