Pull the head and look at the numbers etched in the edge. Some are done by a machine, and some are hand etched. If it's hand etched it'll probably be a 3 part number.
EEK needle is the typical go to needle for the 2/1 carb set ups. Over the years it has proven to fix the mid range stutter/hick up that is associated with 2/1 carb set ups on banshees. That is a Keihin needle though. So make sure you get a keihin carb and the info to sort it out will be out there as there has been numerous fella's sorting them out over the years.