The Milwaukee M18 SWITCH TANK 4 Gallon backpack concrete sprayer kit is the industrys first interchangeable tank design with no manual pumping. Designed to meet the needs of concrete contractors, the battery-powered concrete sprayer delivers 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 for a wide range of applications. The M18 REDLITHIUM XC3.0 battery provides up to 12 tanks of spraying per charge. The 4 Gallon concrete sprayer tank assembly has a dual diaphragm pump for longer pump life and Viton seals for increased durability against harsh chemicals the tank also has a wide mouth opening for easier pouring and a strainer that filters debris from getting into the tank. The backpack frame includes wide straps for added comfort during extended spraying applications and a handle for convenient transport and storage. The 4 Gallon concrete sprayer is made up of two components the M18 SWITCH TANK powered base and the SWITCH TANK 4 Gallon concrete sprayer tank assembly. The powered base includes the motor, battery compartment, and REDLINK electronics. The interchangeable tank assembly includes the pump, hose, and wand. The isolated pump, hose, and wand design allows tank assembles to be added for different applications, eliminating cross-chemical contamination. It also allows the tank assembly to be replaced at a lower cost of ownership compared to replacing the entire sprayer. The powered base is also compatible with SWITCH TANK 4 Gallon sprayer (49-16-28PS) and 4 Gallon water supply (49-16-28WS) tank assemblies. The M18 SWITCH TANK 4 Gallon backpack concrete sprayer is part of the M18 system which is fully compatible with over 175 tools. The kit also includes one M18 REDLITHIUM XC3.0 battery and an M18/M12 multi-voltage charger.