This is a Hoppe's Brush known as the Chamber Brush, model 1323P3.
Hoppe's has become the most trusted name in gun care by advancing and evolving technologies to meet the needs of hunters" shooters" and soldiers who depend on their firearms every day. Hoppe's is the only name you need to know for firearm cleaning and protection.
Features:
Keeps Your AR Bore and Chamber Free of Residue
Improved Barrel Life