Electric discharge Machine i.e wire cut, spark eroders, die sinking machines. They use the resin to clear the water of ions which interferes with the conductivity of electrodes or wire
From what i see it should be the same also uses hyrdogen/hydroxl exchange. My concern i would be more this is used for industrial purposes so don't know if it leaves behind other impurities. would be interesting since this stuff is a lot cheaper.
Some of the machines even have mineral filters up to 1 micron with a lifetime of over 10 years without changing any media with self flushing sensors etc so works like a pool pump filter. So if you want a serious ro unit