Upper bed ladder

I bought one and returned it in favor of leaning a stepladder against the bunk. At least the ones I've seen have small round rungs that are murder on your feet unless you go to bed with boots on. Our RV floor was carpeted and the ladder stayed in place fine. Folded, leaned against the edge of the bunk. Four- and Six-foot ladders are common. We needed Five-foot and had to get it at Ace Hardware. And we have a ladder for other purposes. For a dedicated bunk ladder I'd consider a wooden stepladder with the folding parts removed, cut to the exact length needed.