Save Your Motor
They should call these things "Motor Shaft Savers." If you are like me, once you walk to your plane, you will find that the prop happened to tangle itself in the grass and you have a broken shaft... yes, I have broken more shafts than props!!! Anyway, this product will save your props and SHAFTS. I have not broken a shaft since I started using one.
Negatives: The only problem that I have had is if my prop isn't perfectly balanced, it will shake enough at full speeds that the prop will wiggle itself loose... but again, this isn't really reflective of this product. I just need to make sure my props are balanced :-)
I give this product 5 stars. Review by Horn, Tyson