Really two brushes in one. This nylon fill brush was designed for cleaning all the intricate parts of an M-16. This military spec. brush is great for cleaning any type of firearm, especially where a gentle touch is required. The multiple bristle end is perfect for scrubbing all areas of receivers, actions, slides, frames, etc. Use the single row bristles for hard-to-get-at areas. The nylon bristles are rugged and solvent resistant.