Serrated wheel

      For break adjustment  

      This types of adjuster can be seen  as in Chevrolet vehicle , on the wheel cylinder this type not giving a dust boot    There gives   The letter star type of cover  and adjusting screw stays in middel  and at the screw sits  break shoe  Cover that from outside or outside of cap   Gives tith Or   Grip        and rear side of Baking   plate  does it adjustmet by  The lodger hole  by screw driver    Rotate the cap