"THE BRUSH BLOCK HAS TWO HANDLE HOLES, EACH WITH A MINIMUM DEPTH OF 1 INCH, CENTERED ON THE LONG SIDES OF THE BLOCK DIRECTLY OPPOSITE FROM EACH OTHER, AND ANGLED APPROXIMATELY 45 DEGREES FROM THE BRUSH FACE OF THE BLOCK; ONE HOLE IS THREADED TO ACCEPT A 3/4"" DIAMETER 5 THREADS PER INCH ACME THREADED HANDLE, THE OTHER HOLE IS TAPERED TO ACCEPT A HANDLE TAPERED FROM 1"" DIAMETER TO 3/4"" DIAMETER IN 3 INCHES"