Designed for 12 ga. (45") shotguns; 3 leading edges for aggressive cleaning; Heat resistance up to 700 degrees F; Helix shape engages rifling through the barrel; Nomex fibers act as both a brush to loosen and a patch to capture fouling particles; Equipped with 8-32 threaded ends to fit all Otis cleaning components; Nomex is a registered trademark of DuPont; Limited Lifetime Warranty