We have two flying squirrels, an adult male ("Rocky") and a juvenile female ("Phoebe"). After reading reviews of the various cages available, and of the needs of flying squirrels, we decided to order this cage. We are very pleased with it, especially after we made a few tweaks.I was moved to write a review of this cage because of some of the negative reviews that drew attention to its various shortcomings, such as the lack of instructions, the problems with the welds on the wires, and the curious relationship of the shelves and ramps. I understand and agree with these concerns, but I hope I can offer some perspective and suggestions that will lessen the impact of these shortcomings.The instructions. As other reviewers have noted, there are no assembly instructions. I googled "mcage instructions," and found a couple of YouTube videos of similar cages that gave the gist of how to put it together. As several reviewers have commented, it's not hard to figure out, but it did help to watch the videos. The pictures of the cage on Amazon are also helpful. The only thing that was not as obvious was the support shelf that goes under the plastic pan at the bottom of the main part of the cage. It attaches with four screws, two in front and two in the rear (see picture), and the plastic pan slides in on top of it.The shelves and ramps. As one reviewer pointed out, the ramps are not quite long enough to reach from one shelf to the shelf below it when the shelves are placed in what would seem to be the normal arrangement (i.e., placed on every other cross-bar on opposite sides of the cage). A solution to this problem occurred to me when I noticed that our flying squirrels like to climb up the cage in the corners, I got the idea of moving the shelves away from the side wall on one side so they could climb all the way up two of the corners of the cage without being hindered by the shelves. When I offset the shelves by the space of four wires on one side of the cage (see picture), the shelves were now close enough together horizontally so that the ramps would reach the shelves on the opposite side. So this arrangement allows the squirrels to climb two of the cage corners from bottom to top, and it allows the shelves to be spaced evenly top to bottom in the cage with the ramps connecting each shelf to the one below it (see picture).The welds. Our cage came with one weld separated. We did not discover it until Phoebe escaped one night. Since she is a little smaller than Rocky, I thought she had squeezed between the wires somewhere where they were a little too far apart. I was testing the wire spacing by sliding my fingers through each pair of wires, when finally in the last row at the bottom of the back of the cage, I found one weld that had separated, probably in shipping. The wire was flexible enough that Phoebe apparently had no trouble flexing it sufficiently to escape. I used some J-B Weld epoxy to fix the loose wire (see picture). Then on to the task of recapturing Phoebe: after spending a half hour chasing Phoebe around our first floor with a butterfly net and an old tee-shirt, we pondered how we were going to get her back into the repaired cage. At one point, we saw Phoebe climbing on the outside of the cage, trying to interact with Rocky, who was still inside the cage. We have a couple of bonding pouches for the squirrels, and my wife had the idea of hanging one on the outside of the cage. Sure enough, Phoebe climbed into the pouch, and we were able to get her back inside the cage. Since repairing this one separated weld, we have had no escapes for over a week-and-a-half. Now for the perspective on the welds... As I was looking for where Phoebe had gotten out, I found myself thinking, "There sure are a lot of welds on this cage!" By counting the wires in several of the panels, I was able to calculate the number of welds that went into manufacturing this cage. There are at least 7,860 individual welds! While I am all for quality control, we have to consider what it would cost to inspect and test each of these 7,860 welds to ensure that they are strong enough to survive the vagaries of the shipping process. This added manufacturing cost would have to be passed on to the consumer, considerably raising the price of the cage. As I thought about it, I decided I was happy to put a little "sweat equity" into the cage by doing that inspection myself and applying a little J-B Weld to any separated weld. As anyone knows who has shopped around for a cage this size with this feature set, it is easy to pay twice what this cage costs.So, the bottom line is, this is a great cage (especially for the price), but we have to be aware that while 99.99% of the welds may be perfect, one or two may have separated during shipping. Probably it is sufficient to check the ends of the wires on each panel and see if any of these have come loose. Then if so, pick up some J-B Weld and re-bond them. All things considered, I think it deserves five stars.