The Green Gorilla ProLine Vi Pro System uses Smart Pressure Technology (SPTTM) packaged in a detachable, rechargeable, lithium ion power pack which electronically pressurizes and maintains the air pressure in the tank. Due to the latest power density technology, the lithium ion power cells are maximized when air is pressurized in the tank. This leads to a full day of spraying with just one charge! SPTTM provides the optimum pressure for even distribution of pest control products - no more pumping and guessing if the pressure is correct. SPT allows for precision delivery of chemicals and a reduction in spray time