The Preval Sprayer is a great little aerosol sprayer for all those small jobs and touch-up work. The complete spray system consists of a power unit (aerosol canister) that screws on to a 6oz. glass jar and a cap for the jar. A single power unit can spray up to 16 ounces of paint, varnish, lacquers, what ever you would spray in a regular spray gun. The Preval Sprayer works well with both solvent and water based materials.