The brush includes a core formed from a metal wire bent into a U and the branches of which are twisted to trap radial bristles between them, the core being fixed to the end of a wand. However the benefit of having a core is lost if the core enters magnetic saturation. The moving element comprises an unloading unit for determining selectively unloading of the products that are found on the shelves and at least one structure for receiving the products unloaded from said shelves. A hinge member may be disposed within the hinge member receiving portion and the hinge member may pivotally connect the door to the shed. Also, the correspondence between travel limit switches and indicator lights makes it much less likely that the installer will miswire the indicator lights.