Magnaflow Carsound Catback Exhaust System (PN: 16795). Fits 2008 Pontiac G8 GT models. Features and Benefits: Material: 100% Stainless Steel Tubing O.D. Size: 2.5in. System Type: Cat-Back TIP O.D. Size: 3in. TIP Quantity: 4 Single/Dual: Dual Exit Position: Dual Rear Exit