The shipping fee is the same whether you order 1 can or 6 cans, so save money and order 2 or more.
This is the standard 12 oz. aerosol spray can of Corrosion Block, that puts out a fine mist. It's the most widely used method for application.
Once you've used Corrosion Block, you'll find many uses for it, so order at least 3 cans to save money on the product and the shipping. It doesn't go bad over time.