Nitrous Oxide Systems, commonly known as NOS, are performance-enhancing setups used in vehicles to increase engine power. They work by injecting nitrous oxide into the engine's combustion chamber, allowing for more fuel to be burned and resulting in a significant boost in horsepower. This system is popular in drag racing and other motorsports for its ability to provide quick bursts of speed. The system typically includes a nitrous bottle, solenoids, and a nozzle. When activated, the nitrous oxide is released into the intake manifold, mixing with the air and fuel. Proper installation and tuning are essential to prevent engine damage and ensure optimal performance.