BUT!!!!!! If you look at the non adjustable one on the top there is NO metal looking alike piece thingy magingy. lol
No those float switch can't handle high voltage. You run those to a breakout box for Apex or other controller just to get the signal and turn on an outlet. I'm not sure what you are trying to use a float valve for but sounds like straight from the RODI to your sump??? Not a good idea for top off. I use the RODI to fill up a brute trash can and shut off when it's full. And the float switch I use a few to get water level signals to my Apex.
Using this for over 5 year for RODI and no rust