WOW... Why have I been wasting my money on other flimsy folding cages for LITERALLY YEARS... We've had every kind of DOG you can imagine from Jack Russells to Great Danes and if you know anything about Jack Russells, I'm sure you know their ability to escape any cage at any cost! This cage should be the industry STANDARD when it comes to dog cages. I purchased the [54/48/38 inch Heavy Duty], (the biggest one available) and it came exceptionally fast (3 days early) and wasn't very difficult to put together.One of the plastic pans I received had a small little crack/split in the corner (about 1/2 inch), but I don't think that is going to ever get worse or pose a problem so it's not that big of a deal for me. My only gripe is that they didn't label which piece is which, and 3 pieces are almost identical. The instructions are fairly vague and being the "I don't need instructions" kind of man, looking at the very simple instructions, I kind of winged it and found out the hard way that there is a WRONG way to put this thing together. My only suggestion would be for the manufacturer to place a sticker on the "Right Front of Front Panel" piece or pointed out in the instructions how to distinguish that piece specifically. The image on the instructions shows the leftmost bottom frame (of the Right Front of Front Panel) being slightly thinner, however, it is extremely unlikely that an average consumer would notice the minor detail. Both of the "Rear Panel's" look almost identical to the Right Front of Front Panel. You'll know you did it right if the plastic pans slide right into the slot under the cage from the front of the cage as the instructions show! Took me a few minutes to realize why the pan on the right side of the cage wouldn't go in from the front, I wedged it under from the side and then started my investigation as to why it doesn't slide in from the front, as Step 8's image shows LMFAO!Overall it isn't rocket science folks, it's a bolt here and a nut there and BAM you got yourself a great-quality cage. I threw it together in maybe 30 - 45 minutes (I would highly recommend having some assistance, as it is a HUGE cage, and it doesn't really stand up by itself while you move around from the front to the back to the side to and then to the other side to connect all the bolts. The quality is unprecedented and I am extremely happy with this purchase, so much so, I took the time to write this review. I am unsure why they would put two doors that open from the top being that it is such a HUGE cage, it's not likely you're going to put your animal in from the top and drop them three feet down to the bottom.One side note, you can thank me later... Go to Wal-Mart or Lowes or somewhere and get yourself a package of those tiny little rubber bumpers, or felt feet (the kind that you use on chairs for hardwood floors). The cage doors (front and both top doors) rattle when the animals move, even while the wheels are locked. The first night, my Great Dane was extremely active and kept getting up and repositioning herself and that cage rattled so much and so loud, it was extremely frustrating and obnoxious. Other than that, I love this cage and will purchase another one from this company/manufacturer, if I ever need another cage.I would also recommend finding a dog bed or some sort of padding for the interior, as the bottom is metal, and I'm sure is extremely uncomfortable if the dogs had to lay on it without some sort of cushioning. I wish the company would make or sell custom-fit padding/dog beds that fit the inside dimensions for their great quality cage, they could make or sell them as a bundle and it would save the consumer the hassle of trying to find something that fits perfectly.Thankfully, we had a large washable dog bed that was sitting on the floor and fit almost perfectly. There's about 2 inches on every side of the inside of the cage that isn't covered by the bed, so we threw a few blankets on top of the bed for the 3 dogs that we put in the cage. They all have plenty of room to sprawl out and move around.