Telescopic metal closet rods are easy to install because they expand to fit virtually any closet, and there's no measuring or cutting required. However, because the rods are hollow they tend to sag and even
collapse if you hang too many heavy items on them. To increase the strength of this type of rod, fill its core with a wooden dowel rod. The dowel should be slightly smaller than the inside diameter of the metal rod and about ¼ inch shorter.