Fold down step/ladder?

This my first post so pardon me if it's not in the correct area. I don't drive a truck but I do spend about 40,000 miles a year behind the wheel and occasionally I'll see what looks like a cast aluminum ladder or steps that are mounted on the rear of a flatbed trailer. They look like they can be folded down to use and then flipped back up when not in use. I'd really like to find out where they come from and who makes them. Anyone here know what I'm talking about?

 

I saw a set of these steps on a Reitenouer(sp?) trailer a few weeks ago. I called them up and they said they don't offer steps on their trailers so it must have been an aftermarket add-on. Thanks for the replies so far!

These steps were actually mounted between the rear bumper and the ICC bar. (If that helps)

 

^^^Thanks!

 

After re-reading your post the ladder that I saw wasn't mounted between the frame rails but they were mounted to the outside of both rails between the bumper and ICC bar. The ladder would be flipped up and latched during tranport but could be flipped down for use. Again, thanks for any help.

 

Nope not ramps, these are definately steps or a short ladder. Two rungs that fold out from the rear and the bottom rung is about a foot or so off the ground when it's out. I'll try to get a picture the next time I see some!