Among several functions, proportional dividers can be used to increase or decrease lengths of lines and diameters of circles, and can they be used to inscribe regular polygons within circles (dividing the circumference of a circle into equal parts). 

Fine piece of drafting equipment-very well made.

 Brass 8 Inches Proportional Divider Nickel Finish

Its Come in a Beautiful Leather Cover As Shown in Photos

This is a Reproduction Item, Not Sold As Antique.

This detailed item measures approximately 8 inches Point To Point and 3/4 inch wide.