The black coils are now used as popular hair ties.  That's right, the plastic stretchy "things", keep your hair in a pony tail and it eliminates "the bump" that sometimes occurs when you put your hair up!   Plus....if it stretches, you just hit it with the blow dryer and it brings it back to the original size!

THIS is what I remember the coils used for!

Photos courtesy:  Michelle Taylor's iPhone and youtube.com