RedMax 4 Gallon Battery Backpack Sprayer is designed to meet the needs of commercial and residential landscape jobs or applications. The internal no leak pump design is safer to use and the pump handle can be stored vertically or horizontally for your convenience. This sprayer can be used with wettable powders and liquids for all applications. The 25 psi pressure regulator delivers constant pressure to apply lawn chemical. This backpack sprayer uses an 18 volt battery to activate the pump versus manually doing it. The battery provides up to 4 hours of spray duration on a single charge or 50 gallons of liquid. The impact resistant battery compartment keeps the battery concealed and away from liquid that may cause damage.