Agency Power's mid pipe is a great exhaust upgrade for the Nissan GT-R. The increased diameter pipes allow exhaust to flow more freely through the entire system. This free flowing exhaust is what allows your GT-R to produce more power. The mid Y pipe upgrade can be used with a stock system or with any aftermarket system. The 304 stainless steel is durable and utilizes two mesh sections that bend and flex while preventing exhaust leaks.