This read-only object is the index (1 to 4) identifying which LNB a given row of LNB configuration applies to. This lets a single MIB table describe power, voltage, and frequency settings for up to four independently-controlled LNBs on a multi-demodulator CDD-564, so an admin adjusting LNB voltage or current limits must first confirm they're addressing the correct index for the antenna feed in question. On a site with four separate antenna feeds each with its own LNB, an admin troubleshooting LNB power to one feed specifically needs to work with the table row keyed by that feed's index rather than assuming settings apply globally.