Mark, I think Shannon gets these parts from Matt. Matt or Shannon could tell us. Just to add to the story, the head I am rebuilding had the bigger washer on it to start with, I bought the heli used and am in the process of redoing it. I just looked at the head on my E5s and it looks like it has the bigger washer on it, same with my N5c. Looks to me that the new ones in the Synergy packaging are what has changed. I'm sure Matt will let us know shortly.