Garage door remotes operate on different radio frequencies (measured in MHz or Megahertz). The older Marantec remotes operated on 40 MHz, but the newer models use 315 MHz. Unfortunately there are no longer any remotes available that will work with the older Marantec models so you must add an additional module known as a 315 Mhz external receiver, then the newer remotes will work. It is best to have a professional do this procedure for you, or you can call us for help over the phone at [phone_link].