These nitrous bottle warmers wrap around your ten or fifteen pound bottles and support dual (AC/DC) voltage applications. They are available with a Pressure Switch Kit that includes a relay, toggle switch, inline gauge adapter, a pressure sensor, and all other parts necessary to set up your warmer to make your bottle maintain a set pressure while using DC voltage. Warming your bottle is absolutely necessary for nitrous racers, especially during the cooler months. It is the only way to keep the bottle pressure correct with the appropriate amount of liquid nitrous in the bottle. inaccurate bottle pressure can cause the car to be harder to tune correctly due to inconsistency and also hurt its E.T.