2" x 3" or 3” x 5” white vinyl sticker.

Some history to go with that sticker?  The three white stripes/areas represent the North, West and South Sides.

The top blue stripe represents Lake Michigan and the North Branch of the Chicago River; the bottom blue stripe represents the South Branch of the Chicago River and the Great Canal.

The first star represents Fort Dearborn (though it was the last to be added to the flag) with the six points symbolizing transportation, labor, commerce, finance, populousness, and salubrity.

The second star represents the Great Chicago Fire of October 8-10, 1871.  Those six points signify religion, education, aesthetics, justice, beneficence and civic pride.

The third star is for the World's Columbian Exposition (a.k.a. The Chicago World's Fair) in 1893.  The points of the third star signify the history of Illinois’ governing bodies:  France, 1693; Great Britain, 1763; Virginia, 1778; Northwest Territory, 1798; Indian Territory, 1802; Illinois Statehood, 1818.

And, finally: The fourth red star

The fourth red star, added in 1933, represents the Century of Progress Exposition of 1933.  Six points for significant attributes: world’s third largest city, Latin motto “Urbs in Horto,” “I will” motto, Great Central Market, Wonder City, Convention City.

^ ^ Thanks to Chicago Public Library's website.  Read MORE Chicago History facts over on chipublib.org.