Nitrous Express restricted nitrous class systems are guaranteed to make the most power per jet size of any system on the market. If you don't make the most horsepower or are not 100% satisfied, NX will gladly take the product back and give you a 100% refund. RNC (Restricted Nitrous Class) systems are designed to maximize the amount of pure, liquid nitrous delivered through a limited jet size. These systems include special high flow plates, a .375 orifice Lightning 375 nitrous solenoid, .187 orifice Lightning fuel solenoid, 8AN supply line and a Lightning 500 bottle valve. Conventional Restricted Nitrous Class systems feature a large orifice center bar nitrous plate that has only one nitrous jet and one fuel jet. Gemini Restricted Nitrous Class systems include a perimeter spray plate that has two nitrous jets and two fuel jets.