Car Performance Exhaust Kits For Sale Cat Back, Axle Back, Downpipes Invidia Gemini R400 Stainless Steel Catback Exhaust w Signature Series Invidia G35S G37 Sedan 4dr Q300 Rolled Titanium Tip Cat back Exhaust S Invidia Exhaust Kits & Upgrades Aftermarket Car Exhaust Systems In. Invidia Gemini exhaust systems are designed for primarily dual exhaust vehicles. Most Invidia Gemini exhausts are true dual exhausts systems. As with All Invidia Exhausts, the Gemini catback exhaust systems combine top quality, design and performance. The Invidia Gemini exhaust system is CN machined and constructed with high quality mandrel bent SUS304 stainless steel tubing and manufactured using robot TIG welding and feature a fully polished finish. The Invidia Gemini muffler was focused on keeping a deep and toned exhaust sound that is not excessively loud. The Invidia Gemini exhaust systems are of a Cat Back design which replace all the piping from underneath your 2017 2021 Honda Civic Si Sedan after the catalytic converter. Most Invidia Gemini catback exhausts are available in 3 tip styles: rolled stainless steel tips, rolled titanium tips, straight titanium tips. Invidia Exhausts feature available Titanium Burnt Blue Exhaust Tips as well as full Stainless Steel Full exhaust systems. Full Titanium systems are also available which reduce weight and add performance. Piping diameter 70mm Tip diameter 101mm For Off Road Use Only.