Specifically designed for the maintenance of the AR10/15 and similar models. The chamber brush is made from a double brush with two different diameters: the first segment, made of bronze, cleans the chamber itself, while the second segment, made of stainless steel, cleans the firing pin entrance. With American threading. Length 8 cm. For caliber 7.62/30/308. Gross weight: 25 grams. Pack of 3 pieces.