Made of space-age, polymer bristles, the tips are "feathered" to eliminate scratches. The brushes are handcrafted using precision CNC controlled machines in the Silicon Valley. These are not gimmicks. These brushes are well thought out, precision tools that are made to last. They reach deep into wheel openings and scrub both the opening and the lug nut. They can also be used to clean narrow wheel slots and around tire stems. They are absolutely guaranteed not to scratch any polished wheel. The Lugnut Brush is available with a comfortable, ergonomic, handle for hand use or with a 3/8 inch, tri-lobed, shaft for use with any cordless drill.