The Chapin 4 Gallon ProSeries II Internal Piston Pump Backpack Sprayer is a high-performance backpack sprayer that works with various chemicals and liquid mixtures. To prevent spraying issues, its dual-action piston pressurizes the pump on both the up and down strokes. Users can utilize the three nozzle options for their desired application, especially in larger areas. This sprayer has an in-tank removable filter for quick cleaning and debris collection. It has an operating pressure of between 35-45 PSI. Suitable for insecticides, fertilizers, and other agrochemicals. Excellent for spraying on brushes, trees, yards, gardens, and fence lines.