The 21 MTC adapter board is suitable for digitising a loco without interface and when installed allows the option of removing the decoder easily.
The adapter board offers a possibility for installing a decoder with 21MTC connector. This decoder is simply plugged onto the board. At the other end 21 annular rings make the clean wiring of your loco possible. A neat conversion can be made via this adapter board and enables you to use all additional functions of the 21MTC connector (e.g. loud speaker outputs).