It is perfect for grinding and polishing of cementitious toppings (overlays or screed) and concrete. Thanks to its flexible pads it is also a good problem solver in case of minor low spots when grinding and polishing concrete. Size Available:9'',11'',13'',17'' Grit:50,100,200,400,800,1500,3000# Especially after grit:400#,800,1500,3000# very good at glossy polishing