My Speed Master red brushes both large and smaller say Speed Master by EZ Detail Brush.
My guess is they are the same material.
BTW, they are an awesome brush. Newer style 17-20 inch wheel barrels are a breeze to clean with these brushes.
I have recommended the Wheel Woolie brushes to friends as well, the forum and friends seem to love Wheel Woolies too. I have not used the Wheel Woolies. If you have smaller wheels I'd recommend the smaller Speed Master brush.