The M18™ SWITCH TANK™ 4-Gallon Backpack Sprayer delivers the industry’s first interchangeable tank design with no manual pumping. Designed to meet the needs of professional landscape maintenance, the battery-powered backpack sprayer provides you with instant, constant and adjustable pressure up to 120 PSI and a 25 ft spray distance. The 5-mode pressure adjustment knob adjusts the pressure between 20 – 120 PSI, giving you the capability to complete a wide range of applications. Our M18™ REDLITHIUM™ XC3.0 Battery (sold seperately) provides you with up to 12 tanks of spraying per charge. The 4-Gallon Sprayer Tank Assembly features a dual diaphragm pump for longer pump life and Viton® seals for increased durability against harsh chemicals.