This really is a win-win situation. The Mirka Edge Protector simply clips onto the DEROS 150mm. When sanding into a corner it protects the vertical face of the work preventing scratching or damage. At the same time it protects the edge of the DEROS’ pad from damage from contact with the vertical face. The Edge Protector doesn’t interfere with the performance or efficiency of the DEROS. It is easily removed when not required. Win-win.-bg