Old piece of tackle

Dads old tackle box. Anyone know what it is ?

Looks like a Cinch Tie knot tying tool. Cabela's still sells them.

Thanks guys now I know what it is.not sure how to use it but will put in my collection of vintage stuff.fyi this one is solid brass and next to an old metal deliar scale.

It's a knot tying tool.  I have one.  Forgot the name of it, and haven't used mine in several years, but it works really good.

It's for tying knots,

Hook sharpener maybe.