Those of us of a certain age will remember chalkboard erasers, and sometimes being given the dusty task of taking them outside and banging them together to clean them. I don't know if classrooms use chalkboard erasers anymore. The National Gallery of Australia actually has one example signed by Joseph Beuys catalogued as art!
The one above was made by the Copp Clark Company Limited of Toronto, better known in our country as a publishing house. The company traces its history back to 1841. Now owned by Pearson Plc, "Copp Clark Limited " is a trading name for what is still the oldest, continuously active publisher in Canada. However, they have dropped the book and game publishing activities, and now exclusively focus on financial and settlement calendars for the world's financial markets. So, you'll need to source your No Dusto Noiseless blackboard erasers elsewhere these days.
For more detailed histories, visit McMaster University (the source of the image below) and/or CoppClark.