As with all of our Exhaust products our 2001-06 BMW E46 M3 Un-Resonated Straight Pipe Section 1 is made from the same mandrel bent Polished T-304 Stainless Steel with CNC Machined Stainless Steel Flanges and feature our Limited Lifetime Warranty does not include  bungs, tabs, or brackets. If you love the “Rasp” The S54 Motor creates this is the Section 1 for you! No restrictions just straight piping for the most sound and power. weight 12lbs and ID of piping is 60mm or 2.36″. Made in the USA   Note: Current lead time for Section 1 un-resonated  is 1 to 2 weeks