Turbo Rollers serve two basic needs. First, it pushes the microtopping, an overlay applied ¼ inch thick or less, across the surface spreading the topping over all areas of the floor. Second, the depth of the ridges on the roller determines the thickness at which the microtopping is applied. It is important to get the material down quickly after it has been mixed. Using the turbo roller helps ensure that your overlay is applied at a uniform depth across all areas of the floor.