The spray tool is a durable and high quality tool which is simple to use and , is used for less delicate work, such as applying lacquers, paints, varnishes, shellac, and other finishes to manufactured articles. A spray tool has two distinct passageways: one for air, the second for paint. As the trigger pulls the tapered needle away from the tip, an increasing amount of paint will flow through the orifice in the cap. At the same time, the trigger actuates the flow of air to simultaneously atomize the paint (in the case of siphon , the fast-moving air over the siphon creates a low-pressure area, allowing the ambient air pressure to push the paint from the cup.)The Fluid Tip sits inside the air cap. Inside the air cap's center hole sits the fluid needle.The sole purpose of the reservoir is to hold paint and to allow atmospheric pressure inside, usually through a non-spill valve or pinhole vent.