Our M18™ 4-Gallon Backpack Sprayer w/ SWITCH TANK™ delivers the industry's best pressure control with no manual pumping and an interchangeable tank design. Designed to meet the needs of professional landscape maintenance, the battery-powered backpack sprayer provides instant, constant, and adjustable pressure up to 140 PSI and a 24 ft vertical spray distance. Features Instant, Constant and Adjustable Pressure Add-on Interchangeable Tank Assembly Run-time: Up to 20 tanks per charge with M18™ Battery on Mode 3 Adjustable padded harness with lumbar support and padded hip strap Dual Diaphragm Pump: For Longer Pump Life Critical seals: Viton® for increased durability against chemicals Wide Mouth Opening for Easier Pouring High visibility tank markings for easy fill management Tank identification stickers Easy access latches for quick battery and tank swaps Compatible Tank Assemblies: 4-Gallon Water Supply (49-16-19WS) & 4-Gallon Backpack Sprayer (49-16-19PS)