This pair of well-made, indestructible brushes are practical, efficient and safe for all wheels. Both have hundreds and hundreds of densely packed bristles, feathered at the tip for gentle agitating of any wheel surface, regardless of delicacy. The bristles are sturdy enough to attack tough road grease and grime on your tires as well. They are constructed of alkaline- and acid-resistant, 2 fibers, mounted on non-slip, heavy-duty plastic handles.