MERCEDES BENZ FLIP KEY REMOTE FKR2-7 MB48 W124 W126 W140 R107 R170 R129 It is compatible with some aftermarket alarms and keyless entry systems with a 315MHz frequency. IT WILL NOT WORK WITH THE FACTORY SYSTEM! You can order an adapter to make it work with your Mercedes-Benz. FREE general programming instructions INCLUDED. This key will need to be cut to match your Benz key.