The Sinclair Case Neck Brushes are used to keep case necks free from dirt and powder residue build-up. Brushes are nylon bristle with a closed-loop bronze core to protect from scratching your case necks. The 8-32 male threads fit the Sinclair Accessory Handle (not included). We offer brush sizes to more appropriately clean today's popular calibers, including 17's and 20's. Brushes are available individually, or complete in the Sinclair Case Neck Cleaning Kit with one of each size brush and the Sinclair Accessory Handle. Mfg: Sinclair International