This kit is to be used with the Z50,XR50,CRF50,XR70,CRF70 & CT70. This kit lets you install a big carb onto your Honda Z50,XR50,CRF50,XR70,CRF70 & CT70 - Such as the 20mm AFT Carb and many more 20-24mm carbs. Comes with new gaskets and hardware as shown. The carb side mounting holes are 48mm center to center.