Feedback on 12V water heater element as solar diversion load

stevenal wrote:
Those 12 V elements look like they are for home style water heaters, not RV.

Yeah I don't think they're the right size for a swappable replacement of an RV water heater 120V element. But it says in loud all caps to not use on grid power as it will fry the element. It's a website for wind and solar and listed as a low voltage diversion load element, so seems like the perfect application if I can get it in the tank.