This is the M Studio MS-105-3D Nitro Pipe Set. The MS-105-3D pipe features a 1-piece design and has been tuned exclusively for the OS105HZ and HZ-R. Maximum power is available in the 13,000-16,000 rpm range. When your rotor speed and gear ratio are set for 16,000-16,500 rpm during cyclic load conditions, this pipe will allow the engine to hold the intended rpm. Package includes muffler, gasket and mounting hardware.