I got the ohuhu one from amazon.
It's a true 12.5 feet, so it sticks up about 18 inches above the roof of my 2000.
The 18 inches is just enough to aid climbing and descending without much risk* of kick out at the bottom.
Very compact to store in rv basement, quite light to carry, and seems reliable so far. It was about $100.
*ladders are inherently dangerous. How you move and how you throw your weight around makes a big difference.