The Lessmann Knotted Wheel Brush With Shank has the following specification:

Wire Type: Steel.
Diameter: 50mm.
Width: 18-20mm.
Shank: 6mm.
Wire Gauge: 0.30.
Max Speed: 15,000/rpm.

The Lessmann Wheel Brushes are fitted with a 6mm shank. The tight filling wire and powerful running makes these brushes excellent tools. These encapsulated brushes have a long service life due to the bedding of wire in plastic, which also prevents end breakage. The brushes have a consistent working width.