If you go to Hangar 9's website, you will find the adapter you are looking for. You may be able to find it at a Local Hobby Shop, if they carry Hangar 9 accesories. I have one, and when you use it, and get the right prop, you can expect to see noticeable difference in speed. I am currently repairing an Alpha that I modified last year. My son in law put it in, and the wing and fuselage got disenchanted with being together. I am retraining them to work together again, will be a taildragger once more. I was using an 11x5 prop, seems to get on quite well with that.