This jet is identified by the numbers 247 being stamped on it but you may also find that there are other needle jets that though having a different series number stamped on them, are in fact identical to the 247 and thus interchangeable. The 247 series are used in the Yamaha OEM version of the VM38 and some others but usually not in the original equipment versions of these carburetors found on other brand production bikes. These NJ’s use a HEX 4/042 type main jet which is a different thread and sizing scale than the round type main jets usually only found in most Kawasaki versions of the VM carburetor.
The lower the letter and number indicates the leaner the jet. Example N-6 is leaner than N-8. These are in 0.01mm increments and the 1/2 size 5’s are in a 0.005mm increments. Only the shown sizes are available.