When you need more scrubbing action than our Ultra-Soft brushes provide, our Detail Factory Boar Hair brushes are the perfect option! These brushes are best for cleaning engine bays, brake calipers, exhaust tips, wheels, and any other surface or vehicle that needs heavier cleaning ...When you need more scrubbing action than our Ultra-Soft brushes provide, our Detail Factory Boar Hair brushes are the perfect option! These brushes are best for cleaning engine bays, brake calipers, exhaust tips, wheels, and any other surface or vehicle that needs heavier cleaning action.The large size is ideal for wheel faces and inside engine bays, while the small size is best for exhaust tips, lug nuts, and other compact areas of the vehicle. The stiffer boar hair also makes these great for scrubbing textured interior plastics.Featuring the same ergonomically designed, metal-free handle as our Ultra-Soft brushes, you will be able to clean longer, safer, and more comfortably than with other detailing brushes.