There are two piece electrical cord liners that go into a hole in a cabinet or box to hold and protect the cord. When put together they form a sort of firewall grommet around the cord. I had a box of assorted ones, but used them up or lost the ones left. I need a dozen more in 3/8 but can't remember what they are called. I tried wire grommets and only got those 2 inch hole through the desk liners or one piece firewall grommets. One of the pieces is sort of "U" shaped. The cord can be run and then the liner pieces installed after ward without removing the plug from the cord.
Thanks.