Anyone know what this tool is for???!!

Found this in a friend's garage. Can you tell me what it is for?
Thanks!

hey LeCougar,
Welcome to Automotive Forums..
does the decal say Blue Point?
That is SnapOn private label; so for sure-
automotive.. then i'd have to say maybe
it assisted in brake wheel cylinder rebuilding?
C-clamp held cylinder, and 3-pronged claw kept cups/caps and spring
inside, while you installed piston??
flag down a SnapOn, Matco, or a Cornwell Tools truck, and ask..