The 61C515 has a detailed faceplate. There are four groups of four LEDs for a total of 16 LED indicators. These indicators will glow when they detect power is going to their corresponding terminal connections. They are numerically labeled 0-15 and correspond with the 16 I/O terminal connections on the lower part of the faceplate. There are 4 additional I/O ports that do not have a corresponding LED indicator. These are labeled alphanumerically C1, C2, C3, and C4.  There is a dial directly below the LEDs that is identified with the letters B, C, D, E, F, and G. Below the I/O ports is an additional dial that is labeled 2, 3, 6, and 7. This module should be inserted into an AutoMax card rack assembly. It has the capacity to take up a single slot within the rack. It plugs directly into the card slot that is located on the rack’s backplane and can then be further tightened into place using screws to secure it to the brackets on the rack.