We have managed to get hold of the original  Maxine Mop.  This is absolutely the best. This brush comes in size 3/8". They're made of natural soft white goat hair so it cleans up ever so easily. It's also flatter than most mops so you can see where it's hitting the surface.  
We are offering these rare brushes at a discount price. When they're gone they're gone as Loew Cornell no longer make these.