Just used this for the first time this morning to get to the barrels...it works amazingly. In fact, I tested it with just water (didn't even use a soap or wheel cleaner, which would have probably sped up the process) and it worked great. It looks big but it actually does a good job at squeezing in between the front calipers and the barrels. According to all information I found, the bristles are made of a patented nylon material that has split ends (almost like microscopic brushes) to avoid scratching any surfaces.
