I can't give this 5 stars because it has Shimano branding, but there are some signs that it's a knock-off. The biggest one being that the Shimano part with the same part number has a barrel adjuster built in and this does not. All of this being said, I installed it, set it up, and on my 1x7 it seems to work fine. Was able to index my derailleur, and everything seems to work as expected. If it makes it through the winter I'll consider giving it the 5th star