NEW Black Ultra Stiff 4 inch LONG Bristle model. This 4 inch diameter brush has the same ultra stiff bristles as the rest of our Ultra Stiff line but the bristles are longer allowing for more reach and a slightly more forgiving brush. Save time and effort cleaning and scrubbing brick, concrete, and stone Durable Ultra Stiff nylon bristles and stainless steel shaft. Dual purpose shaft fits most cordless drills and is threaded (5/16 x 24) to use with DA sanders and professional cleaning machines. 4 inch diameter Ultra Stiff power scrub brush with longer bristles Made in the U.S.A. 4 inch diameter drill powered scrubbing brush features aggressive Ultra Stiff nylon bristles, rugged construction, and a dual purpose stainless steel shaft. This brush fits securely in battery powered drills. Longer (1.5 inch) Ultra Stiff bristles are designed for heavy duty scrubbing and tough stains on garage floors, brick and concrete. See our Black Ultra Stiff drillbrushes in 2inch diameter for cleaning hard to reach spots and 5 inch diameter for larger surfaces. Search the Amazon Drillbrush listings for our complete line of drill powered brushes and scrubbers for every cleaning application