When it comes to hard drive caddies and/or hard drive covers, always - make this a principle of yours - try and stick with the original (genuine) parts, and do your best to steer clear of the aftermarket products. Always!
The reason is simple: I have never, ever gotten an aftermarket hard drive caddy or hard drive cover (or any combination thereof) that's an exact fit. Not once. And I've been buying caddies/covers for 20 years. These aftermarket products WILL (1) have a hard time fitting into your laptop, (2) will not be perfectly aligned upon installation. (3) color/paint/texture, when applicable, will not be an exact match with that of your laptop, and lastly - this is the absolute worst part of it - (4) if it has a hard time fitting in, it's gonna be even more difficult to remove from your computer. Think about this: what can be more insulting to you than ... having a hard drive stuck inside your computer and not being able to retrieve it?
A great example would be the popular DELL D600, D610, Inspiron 600 laptops - the caddy has a external door (cover) attached to it, and the whole thing inserts into the laptop. Well ... with these aftermarket caddies, the first thing you'll notice is that the door (cover) is not firmly attached as the originals were. The fit ain't close to perfect - it doesn't slide easily into the hard drive compartment and you'll have to push/wiggle it all the way in. And finally, if you try to remove it, the door breaks off - leaving you without a grip to pull the rest of the caddy/hard drive out. Now what?
I've had to cut open a laptop once to remove a jammed hard drive due to a bad aftermarket caddy that I had used on a customer's computer. Cost me over $200 in all to undo the damages of a $3 caddy.
Now I ain't condemning all aftermarket caddies. If your computer is of the type where the hard drive/caddy are easily accessible and entirely visible, then an aftermarket caddy may suffice - it still won't be a perfect fit, but at least you won't have a helluva time removing the HDD/caddy from the computer. But if your computer is of the type where the hard drive "disappears" into the HDD compartment, then you'll need an exact fit - something that an aftermarket caddy will rarely do.
I have yet to see even the simplest aftermarket caddy - even just a 2.75" x .75" piece of aluminum bracket with two screw holes and a plastic tail - that turn out to be an easy fit. I have seen plenty of nightmares. Too many to count.
So ... don't be penny wise and dollar foolish: if good, used original caddies are available, stick with it. This is the best advise that any one can ever give you.