This semi-scale rotor head includes additional mixing of the blade holder actuator linkage at a ratio of 2 : 1. This results in well-balanced flying characteristics, and the model has a damped rather than direct response to your control inputs (resembling a 2-blade head with flybar).
Use only the suggested rotor blades for flybar-less rotor heads, respective the scale rotor blades Ord.No. 418 or Ord.No. 419.
Caution
It is not permissible to use this rotor head on a mechanical system powered by a turbine. The only rotor head with 14 mm blade holders which can be used with turbine power is Ord.No. 1005/62.