HKS Super Turbo Muffler Catback Exhaust System 2023+ Nissan 400Z (RZ34)High Dimensional Super Turbo Muffler Debut The essence of technology that combines Exhaust Efficiency and Sound Pressure Reduction. Features: D60. 5 mm x 2 Full Dual Layout While the stock layout has a pipe diameter of D45 mm x 2, this product has a full dual layout with a pipe diameter of D60. 5 mm x 2. This allows a pipe cross sectional area equivalent to D85 mm to be secured while lowering to the minimum ground clearance, which is often seen with