thats a series P... its also a very nice stick, but then again most of what tatuaje makes is good. They are a bit cheaper than the havana VIs but a great smoke none the less... on www.heartfeltindustries.com they have a bead calculator... but like most people will tell you here, just order more than needed, you can never have too many beads and before long you'll be swiping some from your main humi to keep other humi's stable...