The Runyon Surface Prep 4.5″ Syntec Diamond Cup Wheel is ideal for wet, dry or cured concrete, block, stone, paver, brick, green concrete, asphalt or hand grinders. This cup wheel is 4.5″ in diameter and has 16 segments. Double Row cup wheels were the original cup wheel design. They are aggressive for a metal bond cup wheel and tend to leave circle marks due to the way the segment are configured. Light coating removal and general concrete preparation are the typical applications they are used for.