The simplest single-point fuel injection systems consist of a single injector that slots into the throttle body. This injector is similar to other fuel injectors, but it is responsible for delivering fuel to the entire engine rather than just one cylinder. When it is activated, it sprays a fine mist of fuel into the throat of the throttle body, where it mixes with air and passes into the intake manifold. Since that results in the air/fuel mixture traveling all the way from the throttle body to the intake ports, this type of fuel injection is sometimes referred to as a “wet manifold system.”