The circular objects in the image are typewriter erasers, which came with a small brush attached to them. The erasers themselves were made from soft materials like rubber, often infused with fine abrasives. This combination was designed to remove ink or typewriter ribbon marks from paper, which was the primary method of correcting mistakes on a typed document before the advent of white-out or digital editing.

The small brush on the tool was used to gently whisk away the eraser debris left on the paper after erasing a letter or a word. In an age when typewriters ruled the business and literary worlds, these tools were essential to maintaining neat and professional-looking work.