The Silverline DCK4 Exhaust Adapter can be used in many applications where a 4" pipe needs to be connected to a 3-1/2" system. Features: T409 Stainless Steel Construction (Non-Polished) 3 1/2" I.D. X 4" O.D. 6" Overall Warranty ANSA Exhaust Technologies warrants to the original retail purchaser that each Silverline exhaust component purchased from an authorized ANSA dealer shall be free from defects in material and workmanship for 1 Year, when used on private passenger cars and light trucks for personal use under normal operating conditions. The warranty commences on the date of the original purchase and is effective for the duration listed below, or for as long as the original purchaser owns the vehicle, whichever comes first.