Item 2644. 6" Side Extender Bars. The two extender bars are what hold the scroll rods a set distance apart and create the sides of the scroll frame. You will need to order knobs (either #2613 Wood Knobs; or #4332 EZ Grip Knobs) for these to work with the scroll rods. Extra knobs, scroll rods, and extender bars let you create a custom scroll frame, or to add to your existing set. Sold as a pair.