Otis brushes are meticulously designed with a proprietary Tufcor core wire, offering superior resistance to corrosion and ensuring a longer lifespan. This advanced core wire features a tighter twist, significantly enhancing bristle retention, which makes these brushes incredibly durable and effective. Specifically crafted for .40 cal/10mm firearms, these 2-inch brushes fit seamlessly with 8-32 threads, making maintenance straightforward and efficient. The set includes one nylon brush and one bronze brush, catering to different cleaning needs and ensuring a thorough and reliable cleaning experience. Choose Otis brushes for their unmatched quality and performance, perfect for firearm enthusiasts who demand the best in their gear.