It's our main firewall and the first line of protection from the outside! We use it to interconnect our remote locations (that use different vendors and equipment) and let the employees work remotely.
We're a small site with 300 users and this equipment is more than enough for us. We use almost all the blades and the equipment has run smoothly for years.
This NGFW monitors all the traffic outside of the main network, prevents malicious activities, and lets us easily manage network policies to shape our connections.