This 2.5'' green glass ball comes with copper rings that enable a person to use them in different ways for different items.They are mostly used for the common 3/4'' weathervane and lightening rods. Also note these glass balls have different imperfections in them,tiny bubbles,waves, streaks ect.None of which will be seen  unless inspected up close.They are all unique as they are blown or poured glass.

 THE NORMAL 3/4'' WEATHERVANE ROD SET UP IS THAT THE TOP 2.5'' BALL SITS ON THE BEVELED PORTION OF THE 3/4'' ROD AND THE BOTTOM BALL .THE 4.5'' ONE SLIDES DOWN THE 3/4'' ROD AND STOPS ON A BRASS RING.LOOK AT THE SECOND PICTURE TO SEE THE USUAL SETUP.THE LISTING IS FOR THE TOP BALL ONLY !!!!