I am an avid flyer of the Parrot AR Drone 2.0. I first bought a lower end Boca Bearing set and they worked great. But I saw that this set had the tight tolerance rating and wanted to try them. Fantastic! In terms of Boca Bearings service and order performance, it was outstanding with free shipping and very fast delivery of the high precision H06-002C-OS bearings. I also received a free mouse pad with the order – I like surprises!