This eraser by the venerable Czech stationery maker Koh-I-Noor can be used by extending the retractable eraser “lead” with a click, the same way you would with a traditional mechanical pencil. This simple and quaint eraser tool comes in 6 colors: red, orange, yellow, green, blue, and purple. The translucent body is discretely printed with their logo and is equipped with a non-slip grip. The upper part has a clip that you can insert into the pen holders of the Hobonichi Techo. Also available for sale is a set of two refill eraser cores.