I designed it as a buckle, for the test print (showed in photo) I printed it on a 2/3 scale, turned out pretty well.

The real dimensions of the buckle are:

• The diameter of the symbol is 6cm (2.36").
• The buckle is 7.5cm (2.95") long.
• The slots for the belt are 3mm (.11") wide and 4.5cm (1.77") long.