It perfectly replaces the SuperDrive drive of a Macbook Pro 15 "mid-2009 in which I placed a Samsung 840 Pro 256GB SSD.
The kit consists of the cart and mounting screws (not if you want to reuse the original parts).
Replacing the Superdrive is done in fifteen minutes and not suffering from any particular difficulties if you have the right tools and a good tutorial (tutorials are easily found on the internet).
For: build quality, the complete kit and good size.
Cons: the price for anything.
Conclusion: for the price this kit gives you your money's worth, it comes very quickly and not suffering from any imperfection, it is a very good price / quality ratio.