Don't confuse these with other "cheapy" LS headers out there...these are the REAL DEAL! Manufactured from ALL stainless steel, (others have mild steel flanges) they are polished and feature a 3/8 thick flange, 16ga. 1-5/8" primaries and 2-1/2" collectors. Gaskets and bolts included. Reducers sold separately. Sold as a pair. See "Technical Specs" tab for application information.