Duracoat Ultimate Do It Yourself Firearms Finish - Can Only (Matte Black) Unique can within a can technology allows release of the hardener with the simple push of a plunger Listing is for the color MATTE BLACK - in a single aerosol can of DuraCoat Firearm Finish Once activated the formula remains usable for up to 4 weeks Useable on all types of metal, plastic and wood. We recommend completing prep prior to can activation. Then spraying 2-3 very thin layers (coats) approximately 2 hours apart for the best results