1779228386nonpienary916

I work at a thrift store and we get all kinds of weird things in. I've been able to identify 90% of it through asking my dad (or any other old man in my extensive old man network) but this has everyone stumped. The main metal feels like steel, but the tips of the forks seems to be aluminum. The knobs you see here are used to move the center prong back and forth. My car mechanic uncle suggested it's maybe some kind of extraction tool? The corners say 4, 2, 9, and X.

Video of the object:
https://m.youtube.com/shorts/cPW3jl8rL8I

Edit with information gathered thus far:
– I am located in the Lower Mainland region of British Columbia, Canada
– I don't know what else it was donated with
– The numbers appear to be 2, 4, 6, and X
– The prongs close all the way on either side, with the dished aluminum ends making a kind of [ ] shape
– The numbers appear to mark some kind of size, with the X having prongs where instead of the ends meeting up like this [ ] the inner (movable) side nests inside of the outer one
– There appears to be an even resistance no matter which direction the center prongs are pushed
– The knobs do not turn or tighten

Edit with the solution!

Text copied from u/DifficultPepper9499:

"3rd generation shoemaker here. It is used to repair zippers that have metal teeth. It pulls the 2 sides of a zipper together so the teeth mesh. It works just like the the zipper pull on your jeans. It fits 4 different size zippers. It can also be used on nylon coil type zippers. You push the buttons on the sides up or down to bring the arms together."

Thanks to u/SnonJohn and u/DifficultPepper9499 for the ID, and u/Impressive_Edge3960 for digging up this listing for confirmation: https://www.worthpoint.com/worthopedia/glen-zip-zipper-repair-tool-trio-1852239047