Place 7-in. Diamond Rings on any standard variable-speed angle grinder. Available in grits from 30 to 3500, use them for polishing small rooms or doing the floor edges of a larger area. They can polish up to 2500 sq. ft., depending on the hardness of the floor. Use in conjunction with the Hum-B polisher and the Pulse-Bac PB-1050 for a complete floor polishing system. CDCLarue Industries. 866-954-9700.