Edelbrock part #73831 Pressure gauges is an important element in getting maximum performance and consistency from your nitrous system. The 1-1/2" nitrous gauges may be fitted onto a nitrous bottle or just in front of the nitrous solenoid. Braided stainless steel lines are required for all remote mounted nitrous gauges. 2-5/8" gauges are illuminated and come with adapter fittings. Liquid-filled gauges offer additional vibration dampening for durability and long-term accuracy. They are the best choice for competition or severe duty applications.