Several Clifford Matrix alarm systems (made by Directed Electronics – DEI) used multiple remotes that seem to be causing confusion for some people. Clifford sold several two-way alarm systems, such as Matrix 2.2X and Matrix 3.3X, that used multiple remotes. These systems are compatible with one-way remotes with the part numbers 7152x and 7153x (sometimes shown as A-7152x and A-7153x), and also with two-way remotes with the part number 7251x (A-7251X). As if the numbers alone are not confusing enough, the one-way and two-way keyfobs are nearly identical.
Most two-way alarm systems have an LCD or OLED remote as the two-way remote transceiver and standard-looking keyfob remote as the one-way companion transmitter. On these Clifford Matrix systems, though, the two-way transceiver uses LED lights next to each button to indicate receipt of signals from the system control module in the vehicle. There are also LED lights next to the one-way transmitter buttons that simply indicate that the user has pushed it.
Very confusing. If you are buying a replacement remote for a Clifford Matrix system that originally used a two-way LED remote, take care to be certain you are buying the correct replacement keyfob.