Hoppe's No. 9 Tornado Gunsmith's Brush , 20-Gauge Shotgun Special spiral wound design Highly effective at removing fouling Stainless steel loops 100 percent designed and tested 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 20-gauge shotgun