This holds the second of eight possible 192-bit Triple DES receive decryption keys, entered as a 48-character hex string. On a hub modem receiving encrypted traffic from multiple distinct remote sites, separate receive key slots like this one let each remote's traffic be decrypted with its own dedicated key rather than sharing one key across all remotes. A hub site receiving encrypted traffic from a second remote terminal would load that remote's key into this slot, keeping it independent from the key used to decrypt the first remote's traffic in slot 1.