The sander works on the principle of applying vibration: the knobbly wheel shakes the sanding material out through the holes at the bottom of the container. A flap is used to adjust the size of the holes, or to close them altogether. The best sanding results are achieved using a ‘crushing’ setting of 3-6mm, but other materials can be used as well. The container and the lid are made of HD-polyethylene. The sander is delivered in a box.