Durable Material: This scrub brush set is made of premium nylon bristles that won't scratch their surfaces. It can remove all stains and is a reliable choice for long-term cleaning. Quick-change shafts: The brush drill attachment shaft is a standard steel quick-release shaft ( length is 6 inches), easy access with your drill and safe to use, quick connection by sliding straight into your drill then simply tightening. the scrubber drill to the cordless drill, to clean faster and achieve thorough cleaning, saving time and maximizing the role of electric drills. All-purpose drill brush kit : 4 brushes + 1 extension rod, which could clean your bathtub, grout, upholstery, bathroom surface, floor, tile, shower, toilet and carpet, etc. The extension rod helps the cleaning brush clean the gaps easily. and corners.