I installed my MilesRunner inflatable topper this weekend.
First note - do not follow any printed instructions included in the packaging if they say to attach the rails to the truck bed first.
Can’t be done that way.
Go to their website and download their most recent instructions PDF and watch the video.
You basically build this by having the topper upside down, use the included pump to add about 10 psi to the top and cab / front section, and 0.5 psi to the sides. This allow the top to hold the rails as you install them. Follow the instructions to install
The front rail, then the side rails. Fold the plastic lip into the rails and then…
Turn the topper over and lift it onto the bed.
I was able to do this by myself. I put the topper on sideways, then pushed and pulled it into the right orientation. once in place, use the 4 included clamps to clamp it in place. Note - slide the rear clamp into the rails first. Once the front clamps are in place, you cannot get the rear clamps into the rail.
Inflated all sides to 10-12 psi.
Then monkey around with the rear window rail and flaps.
All in all, a good setup.

I drove around, hitting speeds up to 60 mph for a mile or two. Stable. The rear view is, of course, a bit reduced. I’m gonna roll up the screened window and see if that helps with clarity out the back. PS. It does!
Did I mention there are two rear windows? Screened and clear plastic. Either can be rolled up independently of the other.
Take time to learn how to unhook the rear window section, so you can roll it up - bar and windows together - to get access to the back easily. The MilesRunner site has good video on this too.