Most Oxygenics products are Water Sense-certified, meaning you don't have to worry about water regulations. PSI (pounds per square inch) measures water pressure while GPM (gallons per minute) measures the flow rate of the washer. This product performs at 2.0 GPM at 80 psi resulting in supercharged pressure with minimum flow rate, which translates to more savings on your utility bills and more money in your pocket. Installation is fast, easy and completed in minutes. No tools required for a seamless installation process.