Worcester Master Sweep 8"x12"  Brush for Chimney Cleaning.

Oil tempered, 22-ga. steel. The thread-and-spindle design is also used on flat wire and poly brushes. These brushes mate perfectly with Quick Connects that are absolutely essential for quicker cleaning.

Brush has a 3/4" loop on one end and a 3/8" NPT on the other.  It attaches directly to the 3/8" fiberglass rods.