Montana X-Treme .Nylon Bristle Brush for Handguns (8/32 Thread) 40/.41 cal SPECIFICATIONS BRAND: MONTANA X-TREME CA PROP 65: YES CLEANING CALIBERS & GAUGES: .40, .41, 10MM CLEANING ITEM TYPE: JAGS MATERIAL: NYLON DESCRIPTION Montana X-Treme Cleaning Brushes are some of the toughest nylon brushes in the industry. They are made with very stiff, heavy duty bristles and a solid brass core to assure your firearms will get a superior cleaning with minimal effort on your part. Standard 8 x 32 thread.