Alpha Antique Brush Wheel. Grit: 240. Size: 4inch. Type: Snail Lock. Material: Natural & Engineered Stone/Quartz Surfaces. Max RPM: 4,000. Create A Textured Finish On The Edge and Surface of Engineered Stone/Quartz Surfaces. Developed with TYNEX®, A Filament From Dupont, To Ensure Safety and Exceptional Performance. Utilizes A Snail Lock Adapter (SFAT). Fits Most Popular Edge Polishing Machines, Hand-Held Sanders and Polishers. Grits Available: #24, #36, #60, #120, #240 and #320/