Invidia N1 Cat-Back System 06-07 Honda Civic Si - P/N: HS06HCHC3GTP Product Model: INV-HS06HCHC3GTP Size Pipe - 60mm Size Tip - 101mm For a good balance of price and performance, Invidia offers the motorsports enthusiasts a strong line-up of Invidia N1 Exhaust is constructed with high-quality SUS304 stainless steel, CNC-machined flanges, and manufactured with a polished finish. Each system features mandrel-bent stainless steel piping for maximum exhaust flow and reduced back pressure. These sxhausts are engineered to produce strong mid to top-end power gains, as well as an increase in horsepower and torque.