It is a HH gyro, but again, from what I understand, that stock servo is not fast enought to accept the needed signal for spot on tail hold. If you are willing to spend a little, I've read that the Spektrum DSP75 is a direct replacement for the stock in the tail. You only need to reverse servo direction on gyro and radio, and then change mode to digitial and you will have rock steady tail. This servo is available for $18-20, and accepts the 275hz for HH capability. Also, you may want to buy a few extra gear sets, because it's not a matter of if, but when on stripping the gears out of the stocks. They are cross compatable with the above servo.