For the person who wants a subtle custom appearance with all the benefits that a Flowmaster Cat-back exhaust system provides. SOS. (Single out side) systems are the perfect choice. Force II systems deliver a moderate exterior tone and moderate to mild interior tone, and are suited to customers looking for efficiency improvements without a lot of noise. Especially recommended for towing applications. Like all Flowmaster systems, the benefits include improved throttle response, power and mileage. Designed for an easy fit, these systems include all necessary parts and hardware for easy installation.