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I know its probably been answered before, but I'm not really sure what to google to find the answer.
It indicates position tolerance in inches and (mm).
More info on this pdf.
As comments in the question and this answer point out, the "M" in a circle stand for "Maximum Material Condition", as in largest pin width or smallest hole.
Which is a Drawing layout for the Machining, with the GD&T positioning tolerance
The position tolerance M symbol represents Maximum material condition If there is L symbol That represents Least Material Condition.
Required, but never shown
2 years, 4 months ago
1 year, 7 months ago