Switch Blade: I ran the Hitec 225BB on mine for a while ~$24 stormers. Now I am running the Airtronics 94145Z. Look at the 4.8v ratting not the 6.0v as the cars are 4 cell. Mine works in the futaba R123 reciever and the XXXtra that I have. They will not work in the Futaba HRS receiver. The HRS requires digital servo's and 6.0v.