Turtles that are used for surface finishing of stone, granite, tile, marble, concrete and other hard materials. Diamond in combination with composite elements is used as an abrasive.  The diameter of the turtles is 100mm, the thickness of the disk is 4mm. The peculiarity of these cups is that they can polish the surface quickly and qualitatively, while not erasing for a long time. You should not worry about the coloring of the discs, because when working they do not leave any colored traces on the work surface. The seller has a large choice of grit of the turtle.