Drawer slide rail - center mount
A handy person from Fairfax, Marin County, Ca says:
October 3, 2015
Overall length is 22 5/8". Overall width (top to bottom) is 1". Rail is for a glide roller mounted on the center of the drawer. The rear support would be your part, "Rear Drawer Track Socket Product Code: 32-001" (I think). thanks for the help!
Paul from SWISCO responded:
October 6, 2015
Our 32-023 rear drawer bracket might work better for your track. Check it out and see what you think.