The Milwaukee SWITCH TANK 4 Gallon water supply tank assembly is an interchangeable tank powered by the M18 SWITCH TANK powered base (Nt included). The water supply tank assembly includes the pump, 10 Ft. hose, and quick-connect. The design allows tank assemblies to be added for different applications, eliminating cross-chemical contamination. It also allows tank assemblies to be replaced at a lower cost of ownership compared to replacing an entire water supply. The 4 Gallon water supply tank assembly has a dual diaphragm pump for increased durability and longer pump life. The water supply tank also has a wide mouth opening for easier pouring and a strainer that filters debris from getting into the tank.