SOLO® 425-101 4 gal Piston Pump Backpack Sprayer with Carry Handle. Built for comfort, built for convenience and built to last. SOLO's ergonomic design contours to your back for greater comfort. With a proven piston pump, you will be reliably equipped for applying spray liquid or insecticides in your garden. A low number of wearing parts and sturdy technology ensure a long service life and minimum maintenance. The SOLO® 425-101, with a connecting rod-actuated piston pump, can produce a wide pressure range of up to 90 PSI and is capable of performing virtually every spraying task. Easily and effectively handles liquid disinfectants, fertilizers, herbicides, pesticides and formulations for tree, shrub and plant protection.