Blue Wonder Gun Black Kits are similar to the Gun Blue kits, except that they produce a dark, glossy black finish on any carbon steel. No expensive tanks or heat sources required. Kit Contains:Blue Wonder Gun Black- 2 Oz.Blue Wonder Developer - 0.5 Oz.Blue Wonder Gun Cleaner - 1 Oz.Blue Wonder Disotec XFR - 0.5 Oz.Notes:Contents should allow refinishing 4 to 6 long guns.Metal must be heated with a propane torch or hairdryerApplies a "factory-like" black finish.Will not affect existing black; only adheres to bare metal.Contains selenious acid, phosphoric acid, gold, silver, copper and nickel.Not for use on aluminum or zinc alloys.