All the Effectiveness of a Typewriter Eraser

If you are about my age or older you remember back before backspace and delete. Before word processing. Before that magic tape in a Brother electric typewriter that would somehow lift a typed character from a page–but only one or two characters back and only if the typebars were perfectly aligned. Back before White-Out. Back when there were typewriter erasers. Typically disc shaped pink erasers attached to stiff plastic brushes, though some later ones were pencil shaped with a stiff plastic brush at the opposite end of the cylinder.