· Floor Grinder, Floor Polisher, Grinding Machine, Polishing Machine, Concrete Grinding Machine, Diamond Grinding Blade, Marble Polishing Powder, Floor Polishing Machine, Concrete Sealer, Diamond Polishing Pad . Company Introduction. The DongGuan Merrock Industry Co., Ltd was founded in 2007. We are the 9th year of alibaba paid member. We have a number of excellent talents .