IRIS Dog Gate - Large to Small Panel Joiner
I have both the 4-panel (short) and 8-panel (tall) IRIS Pet Pens and needed a way to join the two panels together.
So print three of these, and run the hinge-posts down both sides, as shown in the photo.
This thing was made with Tinkercad. Edit it online https://www.tinkercad.com/things/9ajEHHlYL7S