This is the overall major version number of the Check Point software installed on this device. This top-level version is what an admin checks first when auditing an estate for a required major-version baseline, for example confirming all devices have been upgraded off an end-of-support major release, before needing to drill into any individual blade's own version fields. For example, major version 6 across the whole estate confirming no device was missed during a company-wide upgrade off an older, unsupported major release.