MTL CAT Z33 VQ35HR33005 AN004 The Metal Catalyzer that has both high output and high purification system. New for Fairlady Z Z33 Z34 Features By installing this product to HKS Full Dual Muffler + normal intake, it will have 6ps up even for a normal engine. Even the accelerator response has not just better feeling but also our test with G sensor installation has shown the better results and gives sharp response at engine for accelerator work. Both pipe IN and OUT is60.