The 7.62mm brushes are designed for the AK-47 and other similar military firearms. Both brushes features a core wire looped through a brass coupling, threaded #8-36. (Please note, most commercial rods will not accept the #8-36 thread). The chamber brush is configured with a two-step diameter. The first stage of the brush is 7.62mm in diameter and is made of phosphor bronze, while the second stage is made of stainless steel to clean the bolt lock area. The bore brush is phosphor bronze and able to clean .30 caliber/7.62mm firearms.