I had a bellcrank and hated it. I think it is a MKS from Central Hobbies. First, mucho overpriced. It's heavy. It limits travel with the same circular control arm motions as mentioned, only you get double the effect from the servo and bellcrank. I took mine out after much work thru one side of the fuselage with covering ripped off. I went to a single dowel rod and two rods to the split elevators. It is the best thing I've done to that plane. The clevis hitting the control arm on the bellcrank really limited throws and flexed the h@ll out of the single control rod from the servo.