Line Coupler with Data Secure, 2SU MDRC. MDRC device. Line Coupler to connect two KNX lines to each other. Electrical isolation between the lines. Separate bus power supply for each line required. Filter functions to reduce bus load. Supports extended group addresses. Supports KNX Data Secure (from ETS 5.7). Quick application download (long frame support for ETS5). 3 years warranty.