Solve Mystery: Unknown Drawing Symbol 3.0

[resjsu]

Hello,
Trying to set up some production checks and encountered a symbol I have never seen before. I googled machine stock symbols and found something along the lines of what I need to know but could not figure out what the 3.0 besides the squiggly line means. I have attached a PDF with the symbol in question circled.

Any help would be great, Thank you.
-RE

 

[SteamKing]

Can't really tell from the portion shown. Perhaps you could attach another view which shows the piece to which the dimensions and whatnot apply.