After using the 4" Filiflex series, the stone professional then uses the 4" Airflex series. These brushes are available in three additional grits. The Airflex brushes are designed to add color and form a beautiful soft antique look to the stone's surface. Additionally, there other higher numbered Airflex grits that may be used to follwo the standard Airflex brushes. These "Lux" brushes allow you to work the stone to an even smoother looking finish. Using these brushes together allows you to achieve textured, leathered, or antiqued surfaces in a controlled manner.