2.25 inch inlet, dual 2.25 inch outlet. Less than 5,000 miles on it. I need my garage back, so clearing some parts out. There is a 2.125 inch adaptors stuck on the inlet, but the adaptor will slip right over 2 inch pipe. I was running them on an off topic car, but that car is gone and its replacement would not sound good with them. Asking $80 plus shipping.