Our 304 Stainless Steel and 6061 Aluminum Transitions are offered in three different types and are perfect for building your custom high performance exhaust systems. Conical transitions are smooth and true cones that offer optimal exhaust flow and over large transition range. Step-Up transitions are a great transition for someone who is not looking for as large of a transition range. Slip Fit transitions are the easiest to fabricate with since they allow you to lapjoint your welds.