CNC cut and formed 
Tig welded 1/8" PNO steel
Bolt on to factory RS4 holes (requires drilling and tapping of 4 new holes)
Includes (2) Radfab 2" billet hangers, (2) Radfab stainless tabs, (2) PNO brackets and grade 8 zinc 5/16" hardware.
Raw finish
X-pipe with tabs installed available