The Edelbrock Nitrous Bottle Heater thermostatically raises the pressure when necessary by applying heat to the bottle. Consistent bottle pressure (900-950 PSI) is an important element for proper operation of your nitrous system. The 12-volt DC bottle heater is for 10 pound and 15 pound bottles. It comes with all necessary hardware and includes Velcro straps for quick and easy bottle removal. It is sold individually.