aFe Power 48-46214-YC Twisted Steel Header and Y-Pipe (Non-CARB Compliant) Headers are constructed out of 16-gauge, 1-7/8" mandrel-bent stainless steel 3-to-1 formed merge collectors Y-Pipe is constructed out of 2-1/2" mandrel-bent stainless steel tubing Incorporates high-flow, 48 state-legal 200 cell catalytic converters Manufactured and Assembled in the USA