I got to say, the Hitec HS 55s are awesome awesome little mini servos. I AM USING ONE IN A .40 SIZE SAITO 72 POWERED TOPCAP PROFILE and its HARD MOUNTED directly behind the motor as a throttle servo and it has been great (knock on wood). I also ordered another 3 more for my shockflyer. They are great servos and all my dozen or so have worked perfectly.