This specific build is a common choice for technical labs and simulations: : To use this image, upload it to the /opt/unetlab/addons/qemu/fortinet-FMG-v6-build1183/ folder on your EVE-NG server.
It sounds like you’re looking at a specific firmware or software build for a Fortinet FortiGate-VM (specifically the FortiManager fmgvm64kvmv6build1183fortinetoutkvmzip work
Installing an old build exposes your network to known exploits. This specific build is a common choice for