Just as the MX-800 is for all intents and purposes the same as the MX-850, the MRF-250 is the same as the later model MRF-200s. The MRF-300 will also work with the MX-800. The MRF-350 may or may not work with your MX-800 depending on how close its frequency is to the narrow band that the MRF-350 uses. As such, it's not recommended that you use the MRF-350 with an MX-800. None of the MRFs will work with other brand remotes.

Mike
www.SurfRemoteControl.com