Wheel Woolies products came from USA.  The head of the wheel woolie made of 100% polypropylene, some kind of soft fiber.
The advantages for this product are, the head of the woolie holds a lot of water or soap to help to clean the wheel easier and more safe, like a wash mitt.

They are different from most of the other wheel brushes on the market, no dirty water will splash to the user while washing, there is no metal, so it reduced the risk of scratching the wheel like some others brushes with wires . The plastic handle is bendable (but not like 90 degrees) , so you can also wash hard to reach area.

A set of WW kit comes with three brushes, Large (18" long, 3" dia. head), Medium (12" long , 2" dia) and Small (8" long, 1" dia.).

I use large to clean the inside of the wheels, it can reach deep inside. It can also clean wheel wells, then I use the medium one to clean any smaller gaps. The small WW can clean even smaller area of the wheels, you can also use that for other area like the holes of the front grills.