This is 4 turnout motor front end circuit boards for the m83 decoder. It is for using turnout mechanisms with motors with an end shutoff feature in the end stop position. This can only be used in conjunction with the m83 (60831/60832). When you are operating such mechanisms with the m83, you can program the set speed as well as a slow approach to the end position.
Find more Märklin explanation videos on our YouTube Channel