California Proposition 65: This product contains a chemical known to the State of California to cause cancer. High density metal hub construction. Designed and manufactured to be the most cost-effective tool for applications requiring a 3 in or 4 in radial brush. Ideal for use on straight grinders and stationary machines such as bench or pedestal grinders and buffing lathes. Featuring Weiler's solid ring construction, these radial brushes are available in heat-treated steel, type 302 stainless steel and brass wire for use in a wide variety of applications..