These slab rollers, designed for ease of use and efficiency, are rugged workhorses that will stand up to everything your students roll their way. The circular handle moves the roller through a double cable system, with cast iron mounted ball bearings for complete rigidity. Convenient canvas-covered boards make picking up rolled slabs easy. The thickness of the masonite sheet bed can be varied from ¼" to 1¼". Heavy-duty steel pipe construction.