I had the advantage of once having children. They went through audio devices. Not all devices have these inserts. But sometimes you get lucky. Better products seem to use them. Like Sony, Panasonic, Norelco
I once had a baby food jar full of them. But they're all gone. Or at least lost in the maze of junk I have. You drill a smaller hole than the insert. And then press them in.
smo-joe
