A hollow tube that fits between two fixing pieces that are attached to a unit- the tube can revolve

Your post is very confusing. Care to try again? Tom

You need the end pieces, and have the tube? Go to a hardware store with the tube and get closet pole supports. They are wooden or hard plastic, and you screw them into whatever's on each side, presumably cabinets.

Just a guess; I too am confused by the question..

Show us a picture.