Detail Factory Crevice brushes have shorter, stiffer bristles designed to reach into cracks and crevices and ldquo;digrdquo; out dirt and grime. The black Ultra-Soft synthetic bristles are best used around scratch-prone automotive surfaces, such as ldquo;Piano blackrdquo; interior panels found in many modern cars. Like all our brushes, the ergonomically designed and balanced handles allow you to clean longer, safer, and more comfortably than with other detailing brushes on the market.