3 Pack All Purpose Brushes Double ends allow for large surface scrubbing on one end and precision cleaning with the smaller end. Includes brushes with different bristle material for varying levels of aggressiveness when cleaning: nylon, bronze and stainless steel. 1-Nylon All Purpose Brush 1-Blue Nylon All Purpose Brush 1-Bronze All Purpose Brush The nylon brushes are the least aggressive, meet Mil. Spec. and are safe for everyday use. Recommended for use on virtually any surface including wood surfaces. The Blue Nylon Brush features stiff bristles that allow for a more aggressive clean. The bronze and stainless steel brushes give you the ability to scrub hard to reach places where carbon, powder, and copper residue build up. Recommended for cleaning the area around the firing pin and perfect for metal surfaces that require more aggressive scrubbing action. Bronze Brush for use on internal firearm parts only