This head is indestructible. Same bolt pattern and mounting radius as your Dura-Fly blades. Finally an indestructible and truly durable rotor head! May be mounted on any 3mm shaft with the included MPI 3mm prop adapter (ACC364). Our rotor head works with your blade wedges or install our pitch adjuster to fine tune your machine. If you have wanted the finest, strongest most innovative head, you've found it!