This shows how I attached two panels together. They are zip tied together very tightly all around with about 8 tiny zip ties. If you use the mesh panels like I did, then you have to use very small ties, as larger ones won't fit through the holes.

The area where the ramp is attached was neccessary to avoid having the ramp take up area on the sides of the cage. I was concerned about two things. One was the steepness of the ramp since I only used 2 panels, and two was the amount of space for the pigs once they got to the bottom of the ramp. I found that if I did it straight out, that the pigs would run down the ramp and slide into the end of the cage. Doing it this way allowed them much more room and reduced the steepness.

It allows me to move the upper cage around. The upper level is a cage to itself and it attached to the lower level using industrial strength velcro that was glued to the tops of the connectors on both the upper/lower levels. This allows me to remove the top level if I want to.