Nonexistent. Seen a barrel come up for sale somewhere but thats it. Its just a plastic rod so i tried to make one but the plastic i used turned out to be too flimsy. Been thinking about using a piece of an aluminum dowl or something. My father-in-law is a retired machinist and has a lathe among other equipment and keeps sayin hell just make one. I also screwed up the spring thanks to the my homemade rod. I kinda thinking its plastic for a reason though, some flex is probably good. Pretty sure ill be able to find a spring thatll work at least