Single Spiral Tube Brush, Double-Stem with a Threaded Shank (Nipple)
Galvanized steel stem. Overall length is 2-3 inches longer than brush length. One layer of filament twisted between double-stem wires, for added strength.
Double Spiral Tube Brush, Double-Stem with a Threaded Shank (Nipple)
Built to handle the toughest jobs. Heavy galvanized steel stems with very dense wire fill. Overall length is 7-3/4"-8". Two layers of filament twisted between four stem wires, with each layer perpendicular to the other. These tube brushes are the strongest spiral brushes with the highest density of filament.