Specially designed for cleaning M16, AR15 and similar rifles, Both the bore and chamber brushes have a brass core wire looped through a brass coupling, threaded 836, Fits most KleenBore multisection rifle rods found in the Classic Rifle Kits and the All Caliber S170 rod set, The brushes are available in 0, 22 0, 223 5, 56 and 0, 3 7, 62 mm, The chamber brush is configured with two diameters; the first stage of phosphor bronze cleans the chamber area, while the second stage of stainless steel cleans the boltlock area, Bore brushes are made of phosphor bronze with a brass wire core for a longer life for rigorous cleaning, SKU: TCLGR1286