The Milwaukee M18 SWITCH TANK 4 Gal. 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 users 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 psi to 120 psi, providing users with the capability to complete a wide range of applications. The M18 REDLITHIUM XC 3.0 Battery (sold separately) provides users with up to 12 tanks of spraying per charge. The 4 Gal. Sprayer Tank Assembly features a dual diaphragm pump for longer pump life and Viton seals for increased durability against harsh chemicals. The backpack frame includes wide straps providing users with added comfort during extended spraying applications and a handle for convenient transport and storage. The 4 Gal. Sprayer is made up of 2 components the M18 SWITCH TANK Powered Base and the SWITCH TANK 4 Gal. Sprayer Tank Assembly. The Powered Base includes the motor, battery compartment and REDLINK electronics, while the interchangeable Tank Assembly includes the pump, hose and wand. This kit includes: M18 SWITCH TANK Powered Base, 4 SWITCH TANK 4 Gal. Sprayer Tank Assembly, 4 Stainless Steel Wand, Adjustable Nozzle, 4 Fan Nozzle, 4 Angled Nozzle Adaptor.