The VPF front ends are variable pitch feathering which means that the pitch drops as the torque drops off during the motor run. The blades are feathered prior to launch by simply twisting the the spring loaded blade root and engaging the blade root on a catch on the front end. These units could be used for Andrade, Mulvihill and Coupe.

The STD front ends are very simple non feathering, fixed pitch units which the user simply holds after the motor is wound. The prop is released by the hand and the model is launched.