TrippLite LC2400 will adjust voltage from about 90 to 145 to within normal specs but only 20 amps.
As near as I can tell this is about the same as an Uninterruptible Power Supply (UPS) with Automatic Voltage Regulation (AVR) primarily used to protect specific sensitive electronic devices such as computers from fluctuations and power outages - but probably not a whole house or RV. Many companies such as APC make similar devices. They probably contain some sort of battery backup system.
A voltage regulator such as the ones mentioned above are designed for protecting an entire house - but only one leg of incoming power for each device - in other words up to one of our 30amp type plugins. For a 50amp system you would need two of these. Something like the ISB 4000 should be adequate for most power needs in Mexico since we rarely see more than 30amp outlets which limits how much we can run at one time. Few RV parks in Mexico seem to have 50amp outlets.
These voltage regulator devices are meant to be installed in a building so are meant to be hard wired into the house or business and are not specifically intended for RV type use. They are not sold wired with any kind of plugins - no plugs or outlets - you have to wire them yourself or hire and electrician to set them up for RV use. You can run equipment requiring more power such as an A/C with one of these - but probably not two A/Cs. They are intended to run everything in a small house.