On September 26, 2017 at 16:18, Duct Tape said...
the "i" means it works on 433Mhz as opposed to 418Mhz. If you get the "i" series remote, you must use the "i" series RF basestation. If you aren't using an RF basestation, it doesn't matter which version you choose.
If the OP had been using RF, and had in use mrf350, all they had to add was rfx-250i plugged in along side the 418 rfx250, to control both frequencies with one rf base station.