Fit with floor grinder that accept 3*9mm non threaded trapezoid grinding shoes. 【Concrete Surface Preparation Tool】Pulverize the concrete surface to the level of CSP 4-5, expose the aggregate quicker than most diamond segments, it is a great tool to increase the the bonding before new coating. 【Fast Removal Of Tough Coating】Fast removing of epoxy, VCT, glue, mastic and other painting. 【Pack of 3 Pcs】Pack of 3 pieces bush hammer gridning shoes for ASL, Iron Horse, Dr Shultz, Virginia, Warrior, Wolfpack and Vevor floor grinder. To avoid the plate falling off in working, please make sure to put the bush hammer dis on a built in adapter plate, put the bolts on and make sure the magnetic force is strong enough. 【Working Speed Under 1000 RPM】Do not operate with too much pressure, working speed under 1000 RPM. Improper operation can stop the bush hammer roller from running and break the bearings inside. We provide a wide range of bush hammer disc for walkbehind machine. This trapezoid bush hammer plate is with 9mm hole, each roller with 30 tips.