These inlet assemblies offer three key features which have made them a very popular bolt-on for use with a wide variety of Mustang air meters. The cast aluminum finish with blue silicone hoses really dress up the engine compartment and is much more attractive than the factory black rubber assembly. Due to the fact that these pipes are cast, the inside diameter is consistent all the way through the pipe from the air meter to the throttle body. By eliminating the flexible ridges in the factory rubber inlet tubes and by controlling the inside diameter for consistency, a modest horsepower gain is achieved.