The Hoppe's Tornado Bore Brushes are known as "The Gunsmiths Brush." These brushes have a special spiral-wound design that's highly effective at removing fouling, yet won't damage your rifling. The Tornado Bore Brushes stainless stell loops eliminate any bristle ends that could leave scratches. Thread: 8x32Specifications and Features: For the toughest situations and environments Special spiral-wound design that's highly effective at removing fouling, yet won't damage your rifling Stainless steel loops eliminate any bristle ends that could leave scratches Designed for use with .45 caliber pistol