Eraser 6/5 stars quality and performance! The sharpener, if you know how to work with sharpeners, is 4/5. If you want both a sharpener and an eraser together, there is nothing better out there! The sharpener also rotates like the eraser, to close or open its door. To fully open it, to clean it from shavings, then twist it so that it is neither in the open position nor in the closed position and pull it out. I would not recommend detaching the eraser, and not only to prevent it from getting lost, but more importantly, to prevent the bottom part, which is made of relatively thin plastic, from breaking. Convenient tool, the more I use it, the more I like it! The eraser performs even better if you work it a little and eat the corners. The sharpener is very reliable, eraser of top-quality eraser design! PS If you are looking for the best sharpener, then most of the brass ones from M+R are the best in sharpeners.