I purchased two of them to try in my 450 helis. Took a few minutes to figure out assembly and install. Make sure they are all installed the same manner from one heli to another to make adjustments simple. On mine CCW turns make them longer, CW turns to shorten links. I've never heard my CF and FG blades sound so sweet. No more tracking issues!! I'm buying a few more for back up and when i build a new 450 kit this will be installed for sure. Cheers!