What is the name of the widget I seek?

[Tim_T-Bonham.net]

@swampspruce

Try looking up electrical conduit. If you’re running cable you want something like this one or see if you can grab a remnant from an electrical supply shop. There are wall plates and grommets (and maybe a nice Wensleydale somewheres about) that fit right on it.

If it’s just signal cable (computers & networking), he should consider ENT Conduit like this instead.