The medium-stiff polypropylene bristles are ideal for chemically applied solutions which can break down natural brush materials. Long-lasting, resistant bristles are resistant to acids and can be left in chemical solutions for prolonged periods. Hardwood block with 1 threaded and 1 tapered handle hole. 10 In. polypropylene, 2 In. trim. Handle not included. See Model No. 11061 for tapered handle.