1-Gang EZ BOX Old Work Box Extender - CANTEX PVC Pipe and Fittings
Arlington BE2X 2-Gang Extra Large Box Extender
How to Add an Outlet Extender - Pretty Handy Girl
ReceptXtenders Receptacle Outlet Box Extender, Electrical Outlet Extender for Electrical Box and Electrical Outlet Switches, UL Listed – 1/2" Two Gang 5-Pack - - Amazon.com
BES1 | Single | Gang | Box | Extender | Adds | 5/8"