Perfect for cleaning flat surfaces and accessing hard-to-reach places, the versatile 3/4 in. (19.1 mm) diameter Brass Brushes are ideal for cleaning and polishing soft metals like gold, bronze, copper, or brass to achieve a soft, satin, or matte finish. The non-sparking, softer-than-steel brass wire ensures safe use on delicate surfaces. For optimal results, operate the brush at a maximum speed of 15,000 rpm and avoid applying excessive pressure to extend the accessory's lifespan and performance. Pack includes two brass brush accessories.