Suitable for narrow shroud machines. Not recommended for use with 6” ROS tools - the combination of Unipad + wide shroud tools does not give optimal dust extraction. Always use the supplied spacing washers, making sure that a minimal gap exists between the sander’s shroud and the top part of the backing pad, to prevent friction between the two parts. Tighten the screw hard. The backing pad should never turn idle. Occasionally check that the screw is tight.