https://www.rexelusa.com/p/405323/plasti-bond/1-1-2-conduit-clamp-back-spacer/784011211258/pbclb-m150
Plasti-Bond PBCLB-M150 :: 1-1/2" Conduit Clamp Back Spacer :: Rexel USA
Conduit Clamp Back Spacer, Size: 1 1/2 inch, Material: PVC Coated Steel., Cat #: PBCLB-M150, Mfr: Plasti-Bond