I bought the Stromberg Carlson AP-101 Rail Mate a few years back. This mounts beside the factory steps that do not fold back into the inside of the coach like the MorRyde steps. It has a very sturdy square stock bar that fits into a square-slotted bracket with a BIG set screw in it that mounted to the frame where the steps are mounted. It has an adjustable leg for different terrain at the bottom of the handrail. I had to get some square stock with holes from the local big box store to replace the square bar that mounts to the steps, because the mounting screw holes did not align. I weigh over 280 lbs. and it takes me pulling on it and leaning against it with no problems.
Stromberg Carlson AP-101 Rail Mate Step Assist Rail