Features: The surface of the pipe cleaning brush is designed to increase friction streaks, which is helpful to strengthen our cleaning and achieve better cleaning result. The stainless steel tooth mark on the inner side have a strong hardness and a strong ability to remove rusts. It can resist the abrasion, tearing, impacst, corrosion and flattening of bristles, it can clean unfinished metal parts, and will not affect the surface or fine features. There are cleaning teeth mark inside the copper tube brush, and stripes are set on the contact surface with the hand, which can increase the direct friction between the hand and the cleaning brush during our use, which is convenient for applying better force. Suitable for metal, can clean steel parts, machinery, unprocessed metal parts, paint stains, special corrosion without affect the surface. Specifications: Materials: Stainless steel Styles: 3pcs set/9pcs set Size: as shown in the picture Package Includes: 3pcs Pipe Cleaners /3pcs Pipe Cleaners, 6pcs Fitting Cleaners note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.