The IC3600SIXK1C1C is what is called a relay module extender board. This is a type of printed circuit board or PCB. The IC3600SIXK1C1C was created to be a part of the Mark I and Mark II line. The Mark I, released in 1969, and Mark II, released in 1973, were the first two series produced for the Mark line.
The IC3600SIXK1C1C is a large circuit board which is rectangular. At the top of the printed circuit board near the center, there is one (1) small connector port. This connector port is blue in color. This connector port is identified by the initials JA. On either end of the top edge of the board, there is a port which is brownish red. Each contains a pair of two ports. Six (6) small capacitors which are solid yellow are placed at the top of the IC3600SIXK1C1C. These capacitors are arranged in two (2) lines of three (3) each. The capacitors are identified as C7, C8, C9, C11, C10, and C12. Three (3) large capacitors are placed on the IC3600SIXK1C1C. These large capacitors are solid white. Each of the capacitors contains a voltage of one-hundred volts (100V). Their parts numbers are printed on the top of each device. These three (3) devices are labeled as C1, C2, and C3. The part number is BEC-A2093. Three (3) small capacitors are featured on the IC3600SIXK1C1C. These small capacitors are solid yellow. They are named C4, C5, and C6. At the bottom of the IC3600SIXK1C1C on the right half, there are two (2) blue components which are labeled as BJ2 and BJ1.