70 Series - 2.25 Dual In / 3.00 Center Out - Mild Sound; The 70 series utilizes Flowmaster s Delta Flow technology and an enlarged case for improved sound control along with mileage and power gains. Perfect for use on trucks SUV s RVs tow vehicles and high performance street cars where space allows. Constructed of 16 gauge aluminized steel and fully MIG welded for maximum durability.;