Clean the gas tube without disassembly by utilizing this brush, suitable for both AR-15 and AR.308 rifles. This kit includes two brushes. The gas tube brush is specifically designed for use with the clear guide tube, which is included in the AR rifle cleaning kits and the gas tube cleaning kit. It is essential to use the guide tube for the brush to function correctly. Instructions - apply a small amount of Iosso triple action oil to the gas tube brush. Place the clear guide tube over the end of the gas tube. Hold the brush end of the gas tube brush near the bristles and gently feed the brush through with short strokes until it reaches the end. Repeat the process if necessary. The combination of triple action oil and the gas tube brush effectively removes accumulated carbon. The blue brushes are a trademark of IOSSO Products.