The only difference between these kits is the model air compressor that comes with them. The air compressor determines whether a kit is great for honking the horns quickly in succession or providing other duties such as airing up tires or using small air tools.
All of these systems use the same 2 gallon air tank and Shocker XL train horns which means they all have a 3-4 second honk time and sound just as real and loud as a locomotive!
