These are Genuine Keihin 33pwk not immitation knock offs. This flat D-slide carb greatly enhances throttle response and unleashes the beast within! You will be amazed at the HP and torque you have been missing out on. We also carry the 41mm Pro Series for you drag guys or bigger motors wanting more HP. Please call for correct pricing and recommended sizing for your Make/Model. Why waste money on used when we have them so cheap for new?