... quality 3,large gear grinder 4,for concrete,terrazzo,epoxy stair grinder and polisher is not only grinding and polishing concrete ... ,granite, terrazzo, but also for repairing, grinding, polishing, crystallizing millstones.stair grinder and polisher HWG 70 has the quickest motor speed ... Noise 65DB Packing 1000*900*700mm The rotation way of stair grinder and polisher HWG 70: The diamond tools to be ...