The Montana X-Treme Heavy Duty AR-15 Chamber Brush offers superior quality at an affordable price. These brushes are made with very stiff, heavy duty bristles that will not flatten like standard brass bristles, and have a solid brass core to assure your firearms will not be damaged when cleaning. The stiff bristles resist ammonia and oil-based cleaners. The chamber brush is designed for superior cleaning of the lugs and chamber. Standard 8-32 male thread.