for use with most mikuni carburetors, EXCEPT the vm 20!!!!
find the VM20 idle jet here
check the drop down menu for available sizes. we now carry 10, 12.5, 15, 17.5, 20, 22.5, 25, 27.5, 30, 32.5, 35, 37.5, 40, 42.5, 45, 47.5, and 50. if you need em bigger than 50 just ask.
is this for vm18 clamp on? 
Not for VM20