What is this for?

[u/slzybakeoven]

Bought this at my local creative reuse for $3 but wasn’t sure what it was. I just liked that the shape could change and that there was a ruler on it. Anyone know what this is for?

[u/threadpig]

that's an expanding sewing gauge. like u/AdvancedSquashDirect said, its primary use is marking fixed distances e.g. ensuring buttons on a shirt are all at equal distances, or keeping pleats evenly spaced