Sold individually. This part inserts into the wooden hole in the back deck of the futon frame and is used with an oblong roller. The pin from the oblong roller inserts into the hole in this insert.
This is a very simple but critical part that took several months of trial and error to design. If this part is cracked or broken, the oblong rollers will jam in the track and break.
If you need an unusual futon part, let us know and we'll see if we can make it.
Approximate Dimensions
Center Hole: 1/4" Main Diameter: 3/4" Height: 7/8"