The pitman arm connects your steering box to the tie rods.  It can wear out due to excessive play in the steering components it connects.  If worn, steering can become very loose. Be sure to use a new lock tab when you secure it and check the mounting bolt for good threads.  This arm is used on '66 and earlier bugs with the smaller tie rod ends.  NOTE: The very early bugs originally came equipped with a steering box that had a larger diameter shaft.  This box is no longer available.  When switching to the later style steering box on the early cars, you'll need this pitman arm to fit the later box.