This backing pad has been developed for Mirka DEROS 650 sanders only. It permits the user to attach a 125 mm (5 ) pad to a 150 mm (6 ) sander. Attaching a 125mm pad gives the user optimum control when sanding any non-horizontal surface. Edges and undersides are no obstacle with a beautifully balanced DEROS and the small, light and versatile 125mm pad.