Review on DIYHD LT-30E Rolling Library Ladder Brackets For Round Rail - Black (Excludes Rollers, 39-3/4" Extension Track) by Kanwar Mix

So I bought the main roller with the casters for the bottom of the ladder and everything on eBay and then bought the extension track on revain. Overall, it does the job pretty well. But there are things to be aware of:1. Far as I can tell, this same company makes three different versions of this product. If all you get is the base product without an extension, doesn't make a whole lot of difference which one you get, though there are considerations which I'll get to in a moment. But if you need the extension, it's not enough to buy the same brand name. You need to check pictures and make sure you get a compatible extension because the three versions are NOT compatible with each other.2. The version I original bought and thus needed the extension for has a rather wide bracket. It's a bit of over 4 inches from top to bottom which presented a problem since my bookshelf doesn't have 4.5 inch thick shelves. I had to rig something up where I attached a 2x4 to the top of the bookshelf and even with that, the edge of the bracket hangs off the edge of the 2x4 slightly.They have another version with a round bracket which has a smaller footprint but I had already bought this version for the main product so I was stuck. Far as I can tell, only way to know which you are buying is to check the pictures.3. Again, check pictures carefully, especially if, like me, you need the extension because the extensions are from the same company and have the same product name but are NOT compatible with each other.4. I found that even once I had the right extension bar, the extension holder wasn't a perfect fit (it's a little thing that fits into either side and is meant to let them hold together). Thus the two parts are a tiny fraction of an inch off from each other. It's useable but you notice a slight bump when wheeling the ladder over the bump.5. I didn't bother with the screws it came with and just used my own so I can't comment on that. But it was super annoying that it didn't come with a hex key for the brake. Fortunately, I had a huge set of hex keys and found one that fit. Otherwise you risk the ladder sliding right of the rail if you go too far.6. Overall, seems sturdy enough and I'm a fairly large man. It held my weight just fine and didn't buckle at all but as I said, it was a pain because i bought the wrong version of the extension and had to wait for a replacement.7. One more issue which likely won't matter to many but I want to mention it -- this has to be perfectly aligned to be level. As I mentioned, I had to rig up a 2x4 to make this thing fit my bookshelf. Because of this, I attached brackets on the back to make sure the 2x4 was held firmly in place and the 2x4 has a very slight angle now because of that. When I first attached this thing to the 2x4, it wouldn't glide. I had to really struggle with it. I solved the problem by inserting a few thin gaskets behind the top of the bracket so that it was absolutely level.Overall, happy with it and this was by far the least expensive option I found but it was a lot more trouble than it should have been because the company doesn't make it clear they have three different versions. The instructions are also not very helpful though that seems to be common with a lot of these kind of products.