They are made in-house from high grade 304 stainless steel & aluminum. Both offer outstanding ground clearance, are over 50% lighter than stock, & fit like a glove. The muffler options include the 10" or 14" with either the street or race cores. Also new is the EFI Supertune Pro tuning box. These parts combined have yielded a 6 to 8 HP gain along with a much stronger mid range.