A Scorpion Cat Back Exhaust System is a good compromise between performance gains and ease of fitting, swapping out the original components from the catalytic converter back. The systems generally replace secondary catalytic converters where fitted. Some systems may go from the secondary catalyst back where necessary and these are described as Secondary Cat-Back Exhaust System.This in combination with Scorpions exhaust design know-how helps increase power through increased flow-rate and reduced back pressure but leaves primary catalytic converters in place so the car remains road legal and will pass MOTs. Made using precision mandrel worked aircraft grade T304 steel. This is the highest standard steel used for automotive parts and offers excellent corrosion resistance and thermal properties. Scorpion offer a lifetime guarantee for the original purchaser on all their exhaust systems.Scorpion supply their back-boxes with one of their range of tailpipes to suit the vehicle:STW Tailpipes: twin slash cut round tailpipes, sized accordingly to applicationBoxer Tailpipe: single inward rolled, slash-cut rectangular oval tailpipeDaytona Tailpipe: round inner-taper tailpipe, sized accordingly for each applicationEvo Tailpipe: single inward rolled oval tailpipe, 114mm x 87mmEvo R Tailpipe: single inward rolled oval tailpipe, 155mm x 100mmImola Tailpipe: single inward rolled round tailpipe, sized accordingly for each applicationLe Mans Tailpipes: twin inward rolled, straight-cut round tailpipesMonaco Tailpipes: twin inward rolled slash cut oval tailpipes, sized accordingly to applicationStealth Tailpipe: hidden for discreet power and soundSuzuka Tailpipe: single slash cut large round tailpipeTuner Tailpipe: single slash cut tailpipe, sized accordingly to applicationSome vehicles may have multiple systems available with different back box and trim options. These will be listed as seperate products and aren't an option on a single system.