Otis Technology All Purpose Brushes Pack - 3 Pack Blue/Bronze/Steel Small. Includes brushes with different bristle material for varying levels of aggressiveness when cleaning: nylon bronze and stainless steel. Specifications for Otis Technology All Purpose Brushes Pack: Manufacturer: Otis Technology Color: Blue/Bronze/Steel Fabric/Material: Bronze Nylon Caliber: Universal Features of Otis Technology All Purpose Brushes Pack 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 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. Package Contents: Otis Technology All Purpose Brushes Pack Otis Technology FG-316-3: All Purpose Brushes Pack - 3 Pack Blue/Bronze/Steel Small