The SP818 Motorized Backpack Sprayer is powered by a 4 cycle air cooled engine. This 25 L sprayer can achieve pressures from 10-22 bar or 310 psi. We include two spray guns when you purchase the SP818: one gun has dual fine mist nozzles for low level applications, and one gun features a brass nozzle that adjusts from mist to straight stream for higher reach (25' maximum) applications.