This mod is Cummins ISX12/15 and X15 engines with stock sound This sound will be replace Cummins engine sounds in SCS trucks and selectable engines in modded trucks Feature: Cummins ISX12, ISX15, X15 370-605hp engines with stock sound Separate engine and exhaust jake brake sound Air compressor run sound Custom sound attenuation for better and realistic sound fade off Custom sound orientation for realistic sound from different angle New interior noise system for deeper and quieter sound in cabin