Service Dress Blues for male junior enlisted sailors are based on the classic sailor suit in navy blue, colloquially referred to as "crackerjacks" because of the sailor-suited figure that adorns the packaging of Cracker Jack snacks. They consist of a navy blue wool pullover jumper with a tar-flap collar adorned with three rows of white stripes on the collar and cuffs and two white stars, one at each corner of the collar. A black silk or synthetic fiber neckerchief, rolled diagonally, is worn around the neck, under the collar, with the ends tied in a square knot in the center of the chest. The trousers for the uniform are flared as "bell bottoms". The trousers have traditionally featured a broad-fall opening, though changes to the trouser announced in 2012 have added a zippered fly, rendering the buttons merely decorative. A traditional white "Dixie cup" hat is also worn, as well as black leather shoes. For a brief period in the 1970s and early 1980s, male enlisted sailors in paygrades E-1 to E-6 wore a double-breasted blue uniform based on the version worn by officers and CPOs, but with grey buttons and a combination cover with an emblem consisting of a silver eagle and the letters "USN".