Presto Mag Gun Blue is a cold blue formulation that works on all steel (except stainless steel). It is specifically formulated for when you want a deep blue luster on your firearm's metal surfaces.
Specifications:

Type	Blueing Liquid
Size	3 oz
Quantity	1
Bristle Type
Length
Includes
Material	Multiple
Tip Feature
Battery
Thread Pattern
Protects
Suitable For	Firearms
Eco-Friendly