This metal bearing for the main shaft looks nice and works well , in some cases it is touted that it makes your helicopter perform better (less vibration etc.). I have converted from the stock bearing to the metal and found no difference in the performance. I have come to this conclusion regarding upgraded parts, as many as I have bought and tested, for one they do not make your helicopter fly faster, as I have heard some say?? However they do save you money on repairs and what I look for in upgraded parts mainly is longevity of use and price! These are the making of a excelent upgraded part!