Disc return idlers are available in 1 or 2 roll configurations, with the 1 roll design being more prevalent. 

In the case of a single rubber disc return idler, the idler can be mounted onto two brackets which are secured to either side of the conveyor support structure. The mass of the return belt is the only load that return idlers are required to support. They are fitted with rubber discs that contact the conveyor belt and can assist with the removal of fine grain or powdery materials that adhere to the belts surface.