RPi exhaust systems are designed in house and offer an excellent ballance of performance and sound. All RPi exhaust systems are tested under strict conditions to ensure the most performance for your car. For those who want better sound and performance without drawing a lot of attention, we have the ST series. The GT and GtRace series exhaust systems are designed for maximum sound and power. All RPi exhaust systems are made in the USA using top quality T304 stainless steel and come with a Limited Life Time Warranty.