I bought this pen so my two Chihuahuas could get more sun than they do on our daily walks, and so I could sit outside and relax while they do. My yard is unfenced, and since I live in a rental, I can’t just put up a fence so this was a perfect solution. The package includes the eight panels (one has the step-through gate in it) all joined together into one long piece, 4 snap hooks, and six ground anchors. When the pen arrived, I was very surprised at how easy it was to set up, even for an older woman like myself (I'm 56, and not terribly strong physically). I was able to set it up and take it down alone. What you receive are eight panels, joined with metal clips that are folded up kind of accordion style. You take them out of the box and start unfolding them into the shape you want. There is a logo on the gate so you know which way is up, and which side should face out. A plastic pouch is attached to the gate part when you receive it that holds the six ground anchors (see photo) and the four snap hooks that you use to connect the two ends together. Be very careful you set the pen up on level ground, especially if you have diggers. You extend out the panels, then use the four snap hooks to hook the two ends together. Using the six ground anchors, anchor the panels to the ground for stability. The pen works great for my two dogs, including when my youngest jumps up against it barking at passing dogs. The step-through gate is a wonderful convenience as it helps to keep your pets inside when you open the gate to get them out. A big plus when you have fast runners like mine. The only tool I used was a box cutter to open the package. No tools are needed for set up. One pen was not large enough for what I wanted, so I ordered a second one. When you join two together, it makes a really large pen, but it does seem to detract somewhat from the stability. Not to where it’s dangerous, but I would not leave a larger active dog alone outside in it. See photo of the instability (slight leaning) when I opened the gate after doubling the pen size. Setting all the anchors helped some. For a larger dog, I would agree with another commenter that posts would be in order. If you want to take the pen down after each use, a dressing stick with a cup hook on the end is a wonderful help – you don’t have to bend over to find and pull out the ground anchors if you use this. I had one I ordered here on Amazon after a stroke and it makes quick work of those ground anchors. To join two of these pens together does not require any additional snap hooks or tools. See photo for size of two pens combined. UPDATE April 2017 - I am still using these two pens joined together and I would still give them five stars. Two things I have learned that I wanted to pass along: 1. My dogs are small (Chihuahua mixes) and one of them has hit his haunch jumping into this pen. I added slab stones to make steps going in and out after finding a knot on his little haunch from jumping in. (Dogs don't tell you when they hurt, you have to just figure it out) 2. The ground anchors that come with these pens can be challenging to locate when you move the pen. The last time my lawn guys moved the pen to mow under it, they could only find one of the anchors. I found more just like them here on Amazon, though, by searching "tent stakes, simple anchors" and bought those. I also ordered red enamel paint to paint them so they are easier to locate since they almost disappear when you push them down into the ground. I did not receive any discount for this review, I am an honest reviewer. I just like to give great products the praise they deserve. UPDATE: I am still using these two pens over two years later and they are still in great shape - I keep the pens set up in my front yard all the time, and they have held up great with no rusting or breakage, even through the weather. These are truly a great buy and I would not hesitate to buy them again if something happened to the ones I have! It is very easy to lose the ground anchors that come with this product, but I found a great replacement for them here on Amazon - enter this title in and press Search: ALAZCO Galvanized Steel Tent Pegs - Garden Stakes -Heavy Duty. I bought a set of these and spray painted them red to make them easier to find in the grass..